T
a
M

L
C
I

a

A
R
R
A
A

K
G
V
A
A
M

1

r
i
u
b
i
i
c

t
e
p
o
w
c

h
0

Catalysis Today 289 (2017) 20–28

Contents lists available at ScienceDirect

Catalysis Today

j o ur na l ho me page: www.elsev ier .com/ locate /ca t tod

he  multiple  benefits  of  glycerol  conversion  to  acrolein  and  acrylic
cid  catalyzed  by  vanadium  oxides  supported  on  micro-mesoporous
FI  zeolites

uiz  G.  Possato,  Thiago  F.  Chaves,  Wellington  H.  Cassinelli,  Sandra  H.  Pulcinelli,
elso  V.  Santilli,  Leandro  Martins ∗

nstituto de Química, UNESP − Univ. Estadual Paulista, Rua Prof. Francisco Degni 55, 14800-060, Araraquara, SP, Brazil

 r  t  i  c  l e  i  n  f  o

rticle history:
eceived 12 April 2016
eceived in revised form 20 July 2016
ccepted 2 August 2016
vailable online 16 August 2016

eywords:
lycerol oxidehydration
2O5/MFI catalyst
crolein

a  b  s  t  r  a  c  t

The  ZSM-5  zeolite  (MFI structure,  Si/Al  =  40)  was  treated  using  NaOH  and  either  oxalic  acid  or  HCl  to
obtain  hierarchical  materials  with  different  characteristics,  followed  by  impregnation  with  vanadium
oxides  (V2O5)  to generate  redox-active  sites.  The  impact  of  the  multiple  treatments  on the efficiency  and
stability  of the catalysts  in  the  conversion  of glycerol  to acrolein  and  acrylic  acid  was  investigated  and
correlated  with  catalyst  porosity,  acidity,  and  chemical  composition.  The  treated  and  impregnated  V2O5

catalysts  were  subjected  to XRD, 27Al NMR,  nitrogen  physisorption,  TPD-NH3, TG,  and  UV–Vis  analyses,
in  order  to  associate  the  properties  of  the catalysts  with  their  activities.  The  studies  showed  that  the
catalytic  performance  of  the  materials  depended  on  the acidic  and  textural  properties  of  the  zeolites,
which  influenced  both  the dispersion  of V2O5 and  its interaction  with  the  acid sites  of  the  supporting
crylic acid
icro-mesoporous zeolites

zeolites.  All the  catalysts  provided  conversion  values  exceeding  65%,  even  after  6 h on glycerol  stream.
The  distribution  of  products  strongly  reflected  the  effects  of  pore  formation,  acid  treatment  with  oxalic
acid  or  HCl,  and  the  presence  of  vanadium  oxide.  The  effects  of  these  modifications  resulted  in  higher
selectivity  to  acrolein  and acrylic  acid,  a reduced  rate  of coke  accumulation  in  the  zeolite,  and  a  longer
catalyst  lifetime.

© 2016  Elsevier  B.V.  All  rights  reserved.
. Introduction

The growth of greenhouse gas emissions and the limited
eserves of easily extracted fossil fuels have led researchers and
ndustry to pursue new alternatives to replace, even partially, the
se of fossil fuels. As a result, the use of compounds derived from
iomass, such as biogas, ethanol from sugarcane, and biodiesel has

ncreased in recent years. In the case of biodiesel, production has
ncreased and consequently there has been an increase in the con-
omitant formation of coproduced glycerol [1–3].

Glycerol is a focus of green catalytic processes, because
his molecule offers interesting chemical versatility that can be
xploited for the formation of compounds that are currently
rovided by the petrochemical industry. An example of glycerol val-

rization is the synthesis of 1,2-propanediol and 1,3-propanediol,
hich are used as antifreeze fluids in automobiles. In industry, both

ompounds are obtained from the hydration of propene. However,

∗ Corresponding author.
E-mail address: leandro@iq.unesp.br (L. Martins).

ttp://dx.doi.org/10.1016/j.cattod.2016.08.005
920-5861/© 2016 Elsevier B.V. All rights reserved.
a high conversion and selectivity to glycols has been obtained by
glycerol hydrogenolysis using catalysts based on metallic Ni, Ru,
and Cu [4–7].

Another important conversion of glycerol into petrochemical-
type compounds is the formation of acrolein and acrylic acid,
which are used in the manufacture of resins. Acrolein can be
obtained by gas phase glycerol dehydration on acid catalysts such
as heteropolyacids [8], impregnated phosphate groups on metal
oxides [9], sulfated zirconia [10], Nb2O5 [11], mixed oxides [12],
zeolites [13–15], functionalized mesoporous silica [16,17], and
vanadium-silicates [18]. The glycerol can also be dehydrated in
liquid phase [19,20]. Acrylic acid is obtained from the oxidation
of acrolein. The one-step conversion of glycerol into acrylic acid
using bifunctional catalysts with acid and redox sites occurs accord-
ing to Scheme 1 [21–26]. An interesting aspect of coupling the
two reactions is the mutually supporting endothermic dehydra-
tion of glycerol (�H0 = 3.04 kcal/mol) and exothermic oxidation of

acrolein (�H0 = − 61.02 kcal/mol).

For glycerol dehydration using zeolites, maximum performance
of the catalyst is achieved by combining Brønsted acid sites of
medium strength (strong acid sites lead to severe coke formation,

dx.doi.org/10.1016/j.cattod.2016.08.005
http://www.sciencedirect.com/science/journal/09205861
http://www.elsevier.com/locate/cattod
http://crossmark.crossref.org/dialog/?doi=10.1016/j.cattod.2016.08.005&domain=pdf
mailto:leandro@iq.unesp.br
dx.doi.org/10.1016/j.cattod.2016.08.005


L.G. Possato et al. / Catalysis T

OH
OHHO

glycerol acrolein

O

acrylic acid
OH

O
- H

2
O + ½ O2OH

3-hyd rox ypropanal

O
- H

2
O

acid sites redox s ites

S
b

w
p
a
F
i
I
[
t
m
c

e
a
A
t
t
a
c
d
c
t
t
a
o
d

l
s
u
t
a
o
f
s
i
b
a
b
a
t

(
s
i
t
r
a
c
o
m
c
[

o
t
w
z

cheme 1. Glycerol oxidehydration (dehydration combined with oxidation) on
ifunctional acid and redox active sites.

hile weak acid sites are less capable of converting glycerol) [27],
orosity (which enhances the diffusion of glycerol and acrolein),
nd high specific area (which increases access to catalytic sites).
or instance, members of the lamellar MWW  zeolite family, which
ncludes microporous MCM-22, pillared MCM-36, and delaminated
TQ-2, offer advantageous characteristics for glycerol dehydration
22]. Following pillarization and delamination of the MWW  struc-
ure, the strengths of acid sites decrease, but the increases in

esopores and specific area raise the overall performance of the
atalyst [28].

Despite the attraction of lamellar zeolites for use in glyc-
rol dehydration, the laborious multiple steps and the expense
ssociated with catalyst preparation are notable disadvantages.
lternatively, the desilication of commercially available zeolites by

reatment with sodium hydroxide solution seems to be more prac-
ical [29,30]. The alkaline process is simple, with hydroxyl groups
ttacking and removing silicon atoms from the zeolite structure,
reating randomly distributed pores in the zeolite crystals. The
iameter and volume of the pores can be tuned by adjusting the
oncentration of the alkaline solution and by varying the exposure
ime of the zeolite (usually a few minutes) and the desilication
emperature (which normally ranges from room temperature to

 few tens of degrees Celsius) [31–37]. The broad distribution
f mesopore families results in catalytic performance in glycerol
ehydration similar to that of the MWW  zeolites.

A disadvantage of the desilication method is that during the zeo-
ite treatment process, aluminum atoms are removed as well as
ilicon atoms. Silicon species are mostly found in the alkaline liq-
id phase, but aluminum tends to form insoluble oligomeric species
hat can precipitate on the catalyst surface as extra-framework
luminum atoms (EFA). Consequently, the mesopores created are
bstructed due to an alkali-induced alumination of the external sur-
aces of the crystals, and the nature of the acid sites of the zeolite
hifts from Brønsted to Lewis acid sites. This catalytic acid behav-
or must be considered in the design of catalysts by desilication,
ecause EFA sites are selective in converting glycerol into undesir-
ble byproducts. However, the EFA can be removed from the zeolite
y acid leaching; as a result, the selectivity to acrolein is enhanced
nd the diffusion of chemicals through the pores is increased due
o the removal of aluminum species.

In the second step of glycerol conversion to acrylic acid
Scheme 1), redox active sites are required. Vanadium oxides are
trong candidates for this purpose because they possess a very
mportant redox characteristic, namely the capacity to adopt mul-
iple oxidation states. On these catalysts, acrolein is oxidized by
emoving a surface oxygen atom from V2O5, giving rise to acrylic
cid and an oxygen vacancy in V2O5-x. In a subsequent step, the
atalytic site is oxidized and reestablished by feeding an excess
f molecular O2 in the stream (V2O5-x +1/2O2 → V2O5). This redox
echanism and the changes in V5+/V4+ oxidation states during the

atalytic reaction are known as the Mars-Van Krevelen mechanism
38].

In a recent publication, we described additional useful features

f the V2O5/zeolite catalytic system [20]. Besides the advan-
ages mentioned above, vanadium oxides supported on zeolites
ere much less susceptible to deactivation, compared to the bare

eolites. Several parallel and unknown reactions occur simultane-
oday 289 (2017) 20–28 21

ously with glycerol dehydration to acrolein. Byproducts include
acetaldehyde, acetol, and acetic acid, as well as very harmful and
deactivating coke molecules. After catalytic experiments with bare
zeolites, the polymerization of bulky molecules on the surfaces
of the catalysts led to coke formation and a characteristic black
appearance. However, in the previous work it was found that when
a V2O5/zeolite catalyst was used, the coke was continuously oxi-
dized due to the presence of well-dispersed vanadium oxides on
the zeolite surface, which maintained the catalytic sites active for
longer periods.

The aim of the present work was to explore further the multi-
ple benefits of porous V2O5/MFI catalysts in the one-step glycerol
conversion to acrylic acid. The work focused on zeolite supports
prepared by sequential processes of desilication (in NaOH solu-
tion) and dealumination (in HCl or oxalic acid solutions) in order
to tailor the pores and the quality of acid sites derived from either
aluminum in tetrahedral coordination in the zeolite or from EFA.
Improved transformation of glycerol was  achieved on the micro-
mesoporous V2O5/MFI zeolites, due to higher catalytic conversion,
improved selectivity to acrolein and acrylic acid, extended catalyst
stability, and decreased coke formation.

2. Experimental

2.1. Preparation of zeolite supports

Zeolite of MFI  structure (Si/Al mole ratio of 40) was kindly
provided by Zeolyst (USA). The sample was  submitted to alka-
line treatment at 60 ◦C for 1 h using an aqueous solution of NaOH
(0.6 mol/L). Detailed information concerning the desilication proce-
dure is provided elsewhere [30,39]. The desilicated zeolite was  then
submitted to two different acid treatments using aqueous solu-
tions of hydrochloric or oxalic acids. The acidic treatments were
performed under reflux using 0.1 mol/L acid solution. The MFI  sup-
ports were denoted A (parent and untreated MFI  zeolite), B (after
alkaline treatment), C (after treatment using H2C2O4), and D (after
treatment using HCl). After the sequential alkaline and acidic treat-
ments, all the supports (A, B, C, and D) were ion exchanged three
times with NH4NO3 solution, at room temperature. The exchanged
NH4

+ cations were thermally decomposed by heating the samples
for 3 h in a conventional muffle furnace, in air atmosphere, from
25 ◦C to 500 ◦C at a heating rate of 10 ◦C/min.

2.2. Preparation of the catalysts

V-MFI catalysts were obtained by incipient wetness impregna-
tion of the supports using an aqueous solution of vanadyl sulfate
(0.05 mol/L). Approximately 50 mL  slurry of vanadyl sulfate solu-
tion and zeolite was stirred for 1 h at 25 ◦C. The water was allowed
to evaporate under vacuum at 40 ◦C, and the samples were dried
overnight at 100 ◦C. Finally, the catalysts were subjected to a ther-
mal  treatment for 2 h in an air atmosphere, with heating from 25 ◦C
to 500 ◦C at a rate of 5 ◦C/min. The contents of V2O5 in all the sam-
ples was  10 wt.%.

2.3. Characterization of samples

X-ray diffractograms of the supports and catalysts were
obtained at the XPD beamline of the Brazilian Synchrotron
Light Laboratory (LNLS), using a Huber 4 + 2 circle diffractometer
equipped with an Eulerian cradle (model 513) placed approx-
imately 13 m from the double-bounce Si(111) monochromator

(� = 1.377494 Å) [40]. The data were collected in high-resolution
mode, employing a Si(111) analyzer crystal and a Mythen detec-
tor. Structural parameters were determined by the Rietveld profile
method, using GSAS-EXPGUI software [41,42]. The scale factors,



2 lysis T

z
t
C
t

l
i
i
T
a
u
t
B

s
T
a
o
s
s

e
t
1

w
1
1
s
m
X
w
d

t
v
f
t
fl
t
1
p
fl
t
o

2

e
p
a
e
a
fl
h
w
T
d
l
c
i
e
s
p
c

the same protocol as glycerol dehydration, but with the reaction
temperature shifted to 350 ◦C and with 20% of oxygen fed into the
stream (6 mL/min of O2 and 24 mL/min of N2). The O2/glycerol mole
ratio of 4.5 ensured that an excess of oxygen was used.
2 L.G. Possato et al. / Cata

ero shifts, and backgrounds of the peak profiles, together with
he lattice parameters, were refined by fitting with a sixth order
hebyshev polynomial. Pseudo-Voigt functions were employed for
he peak profile refinements. Other parameters were not refined.

The textural properties of the supports and impregnated cata-
ysts were determined by means of nitrogen adsorption-desorption
sotherms obtained at −196 ◦C with a Micromeritics ASAP 2010
nstrument, using a relative pressure (P/P0) interval of 0.001-0.998.
he samples were previously decontaminated by degassing for 12 h
t 100 ◦C under a vacuum of 1 × 10−5 Pa. The t-plot method was
sed to distinguish between the micro- and mesopore contribu-
ions. Finally, the mesopore distribution was estimated using the
JH method [24].

The 27Al NMR  spectra were acquired using a Varian INOVA 500
pectrometer equipped with a 7 mm probe and operated at 4.5 kHz.
he experiments were performed using a spinning rate of 78.2 MHz,
cquisition time of 15.4 ms,  pulse width of 2.4 �s, and recycle delay
f 0.1 s. The 27Al chemical shifts were referenced to an aqueous
olution of Al(NO3)3 (1 mol/L). Each spectrum was the result of 256
cans.

Thermogravimetric analyses of the used catalysts (after the glyc-
rol reaction) were performed with a TA Instruments SDT Q600
hermobalance. The samples were heated from 30 to 900 ◦C, at
0 ◦C/min, under a 100 mL/min flow of synthetic air.

Scanning electron microscopy (SEM) analyses of the samples
ere performed using an Inspect S50 microscope (FEI) operated at

0 kV, with a secondary electron detector and working distance of
0 mm.  After 1 h in an ultrasonic bath, a suspension consisting of the
ample and acetone was deposited on an aluminum stub specimen
ount. The Si/Al mole ratio was determined by energy dispersive
-ray spectroscopy (EDS), using the same microscope. The spectra
ere measured in five different regions, and the composition was
etermined by averaging the results obtained for each sample.

The acid sites of the calcined catalysts were determined by
emperature programmed desorption of ammonia (TPD-NH3). Pre-
iously, a 200 mg  portion of each sample was degassed at 300 ◦C
or 1 h under a 60 mL/min flow of helium. The temperature was
hen decreased to 100 ◦C and the sample was exposed for 1 h to a
ow of 1% ammonia in helium (60 mL/min). After surface satura-
ion, the sample was submitted to helium treatment at 100 ◦C for

 h to remove physisorbed ammonia. The TPD-NH3 analysis was
erformed from 100 ◦C to 600 ◦C (at 10 ◦C/min), under a 60 mL/min
ow of helium. The desorbed ammonia was monitored and quan-
ified with a Pfeiffer vacuum mass spectrometer connected to the
utlet stream of the tubular reactor.

.4. Catalytic tests

The bare zeolite and V-MFI catalysts were tested for glyc-
rol dehydration and oxidehydration, respectively, at atmospheric
ressure. Previously, 100 mg  portions of the samples were heated
t 300 ◦C for 15 min, under a 30 mL/min flow of nitrogen. The glyc-
rol dehydration reaction was performed in a fixed-bed reactor
t 300 ◦C for 6 h, using a solution of 10 wt.% glycerol in water. A
ow of 0.05 mL/min of this liquid solution was introduced to a
eated line using a syringe pump (KD Scientific), and the glycerol
as transported to the reactor using a 30 mL/min flow of nitrogen.

he unconverted glycerol and the reaction products were con-
ensed continuously in a gas-liquid separator kept at 1 ◦C. The

iquid was periodically collected, weighed, and injected into a gas
hromatograph (Model GC-2014, Shimadzu) equipped with a cap-
llary column (Rtx-1, 30 m,  0.32 mm,  1 �m)  and a FID detector. For

ach injection, a known mass of n-butanol was used as internal
tandard. Four drops of standardized solution was diluted in iso-
ropanol (1 mL)  to prevent excess water from the chromatographic
olumn. The GC analyses were performed in triplicate, and the
oday 289 (2017) 20–28

retention times of all the compounds were compared with those of
authentic standards. The glycerol conversions (Xglycerol) and prod-
uct selectivities (S) were calculated using the following equations:

Xglycerol(%) = nGl
input − nGl

output

nGl
input

× 100 S(%) = ni

nGl
input − nGl

output

× Zi

ZGl
× 100

where:
nGI

input and nGl
output are the input and output flows of glycerol;

ni is the flow of the products i (mol/min);
ZGl = 3 (the number of carbon atoms in the glycerol molecule);
Zi = number of carbon atoms in the products.
The deactivation (D) of the catalysts used in the glycerol dehy-

dration was calculated using:

D(%) =
(Xglycerol)at time zero

− (Xglycerol)after 6h

(Xglycerol)at time zero

× 100

The glycerol oxidehydration reaction was conducted following
Fig. 1. Rietveld plots of samples A (parent MFI), B (NaOH), C (H2C2O4), and D (HCl),
using � = 1.3775 Å: experimental (black line), calculated (red line), and difference
plot (blue line). (For interpretation of the references to colour in this figure legend,
the  reader is referred to the web version of this article.)



lysis T

3

3

p
t
t
(
i
c
M
t
p

c
T
0
a
c
T
e
t
p
p
v
t
p
s
s

c
s
a
E
a
a

N
t
s
n
p
f
s
B
o
t
p

T
C

L.G. Possato et al. / Cata

. Results and discussion

.1. Characterization of the zeolite supports

The XRD patterns of the MFI  zeolites before treatment (sam-
le A in Fig. 1), after the alkaline treatment (sample B), and after
he acidic treatments (samples C and D) revealed the presence of
he main reflections related to the MFI  structure: (011), (200), and
051). The samples submitted to the treatments showed decreases
n peak intensity, consistent with the reduction of long-range order
aused by the extraction of silicon and aluminum atoms from the
FI  structure [35]. The oxalic acid and HCl treatments also affected

he crystallinity of the samples, as clearly shown in the diffraction
atterns of catalysts C and D, respectively.

The results of structural analysis by Rietveld refinement indi-
ated unit cell expansion after the alkaline treatment [43] (Table 1).
he removal of silicon (which has a mean Si-O bond length of
.162 nm)  and the consequent increase in the concentration of
luminum in the structure (mean Al-O bond length of 0.175 nm)
aused unit cell expansion from 5236.9 nm3 to 5258.1 nm3 [44,45].
he unit cell expansion was additionally influenced by the pres-
nce of aluminum atoms that remained in oligomeric form inside
he pores of the zeolites. The subsequent acid treatments caused
artial leaching of the EFA, and the structural analyses of these sam-
les indicated changes in unit cell volume. The decreased unit cell
olumes of the acid treated samples (C and D) revealed that the
reatments were effective. The global chemical analyses of the sup-
orts showed growth in the aluminum fraction from sample A to
ample B (Si/Al ratios of 40 and 18, respectively), and growth in the
ilicon fraction from sample B to samples C and D.

Samples C and D were (Table 1) dissimilar in terms of both unit
ell volume and aluminum fraction, due to the differences in the
trengths of the acids used (the pKa values of hydrochloric acid
nd oxalic acid are −6.3 and 1.2, respectively) and the mechanism of
FA leaching. The action of HCl involved solubilization of oligomeric
luminum oxide species, while oxalic acid acted as both an acid and

 chelating agent.
The formation and leaching of EFA was followed using 27Al MAS-

MR  (Fig. 2). The chemical shift peak centered at 54 ppm was  due
o tetrahedral aluminum atoms in the zeolite structure, while the
ignal between 0 and −20 ppm was due to the octahedrally coordi-
ated aluminum of EFA [46]. As mentioned before, the desilication
rocess was not only responsible for the extraction of silicon atoms
rom the structure, but also for aluminum removal, as is clearly
hown in the detail of the decomposed lines for desilicated sample
. In contrast, the parent zeolite contained only a minor amount

f EFA. A rigorous comparison of the NMR  spectra showed that
he peak at 54 ppm became slightly broadened after the chemical
rocesses, because the tetrahedral arrangement of the aluminum

able 1
hemical and textural properties of the bare and impregnated zeolite samples.

Samples Vmicro

(cm3/g)
Vmeso

(cm3/g)
�mo
NH3

A 0.33 0 388 

B  − NaOH 0.23 0.41 464 

C  − H2C2O4 0.21 1.25 406 

D  − HCl 0.18 1.30 529 

Reference Al2O3 0 0.89 110 

V-A  0.26 0 579 

V-B  0.18 0.21 545 

V-C  0.21 0.24 427 

V-D  0.20 0.24 581 

a Silicon to aluminum mole ratio determined by EDX (global chemical composition).
b % EFA determined by deconvolution of the 27Al NMR  spectrum (contribution of tetrah
c Not applicable.
oday 289 (2017) 20–28 23

atoms in the structure tended to distort. The same effect led to
reduced crystallinity of samples B, C, and D.

The relative intensities of the peaks in the NMR spectra were
used for approximate calculation of the amounts of EFA (Table 1).
Comparison of the results for Si/Alglobal and the percentage of EFA
showed that the oxalic acid treatment provided greater selectivity
in removal of EFA without severely affecting the aluminum frame-
work. The micropore volume only changed slightly, from 0.23 to
0.21 cm3/g, while the mesopore volume showed a more signifi-
cant change, from 0.41 to 1.25 cm3/g (Table 1). The reactivity of
HCl was  evidenced by a more pronounced reduction of the micro-
pore volume to 0.18 cm3/g. Dealumination of zeolites with oxalic
acid occurs because oxalic acid acts as a hydrolyzing agent by both
solubilizing and removing aluminum oxohydroxide species, and
forming aluminum oxalate complexes [47]. These complexes have
a maximum size of around 0.64 nm,  which is compatible with the
pore dimensions of zeolites and enables mobility of the complexes
within the pores [44].

The N2 adsorption-desorption isotherms of the MFI  zeolites are
shown in Fig. 3a. Sample A exhibited a Type I isotherm typical of a
pure MFI  microporous structure [48]. After the alkaline treatment,
a hysteresis loop appeared and the capacity of this sample to adsorb
N2 increased, especially at relative pressure (P/P0) above 0.8, due
to the creation of intra-crystalline mesopores. Additionally, the dis-
ruption of the micropore structure of the zeolite in alkaline solution
led to a decrease of the adsorption plateau at low P/P0 characteris-
tic of nitrogen adsorption limited by the micropore size. Analyses
of the BJH pore size distribution (Fig. 3b) showed the creation of
mesoporosity in the supports submitted to alkaline and acidic treat-
ments. The pore size distributions broadened after use of the acid
treatments to clean the zeolite surface, giving rise to additional
porosity.

The acid sites of the samples were characterized by
temperature-programmed desorption, using ammonia as a
basic probe molecule. The TPD-NH3 curves obtained for the bare
and impregnated zeolites are shown in Fig. 4. The bare zeolite
showed well-resolved NH3 desorption peaks, one in the low
temperature (LT) region at around 200 ◦C, and one in the high
temperature (HT) region at around 420 ◦C (Fig. 4a). The reference
sample (�-Al2O3) presented a low amount of desorbed NH3 and a
wide desorption temperature range, characteristic of the presence
of Lewis acid sites. The amounts of NH3 desorbed from the samples
are given in Table 1. The NaOH treatment resulted in increased
NH3 desorption, due to the decrease in the Si/Al ratio (Table 1), in
agreement with the results of the 27Al NMR  and chemical analyses.
Treatment of zeolite sample B with oxalic acid led to a decrease in

the quantity of acidic sites, due to the removal of EFA, as found in
the 27Al NMR  analyses. The treatment with HCl was less effective
in removing the EFA, so the acidity was greater than for the sample
treated with oxalic acid [49].

l of
/g

Si/Alglobal
a % EFAb Unit cell

volume (nm3)

40 12 5236.9
18 29 5258.1
24 5 5250.0
26 11 5236.6
n/ac n/a n/a
n/a n/a n/a
n/a n/a n/a
n/a n/a n/a
n/a n/a n/a

edral aluminum species in the zeolite framework).



24 L.G. Possato et al. / Catalysis Today 289 (2017) 20–28

80 60 40 20 0 -20

D

C

B

A

In
te

ns
it

y 
(a

rb
. u

ni
t)

Chemical Shift (ppm)

a

80 60 40 20 0 -20
Chemical Shift (ppm)

Sam ple B

-13 ppm
-1 ppm

54 ppm

In
te

ns
it

y 
(a

rb
. u

ni
t)

b

Fig. 2. (a) 27Al NMR  spectra of the parent and treated zeolites, and (b) deconvolution of the sample B spectrum.

0.0 0.2 0. 4 0.6 0. 8 1.0

500

a

A
ds

or
be

d 
vo

l.
(c

m
3 /g

)

Relative  pressure  (P/ P0)

 A
 B
C
 D

1 10 100
0.0

0.5

1.0

1.5

2.0

b

Pore dia meter  (nm)

dV
/d

lo
g(

D
) 

(c
m

³/
g)

 

Fig. 3. (a) Nitrogen adsorption-desorption isotherms (filled and empty points correspond to nitrogen adsorption and desorption, respectively), and (b) BJH mesopore size
distributions from the desorption branches.

NH3) c

s
o
l
H
o
t
d
o

Fig. 4. Temperature-programmed desorption of ammonia (TPD-

The TPD-NH3 curve profiles of the vanadium oxide-impregnated
amples (Fig. 4b) were significantly different, compared to those
f the bare zeolites (Fig. 4a), with the LT and HT peaks shifted to
ower temperatures. The LT peak increased in intensity, while the
T peak ended at around 450 ◦C, instead of at the value of ca. 550 ◦C
bserved for the bare zeolite. This could be explained by coverage of
he strongest acid sites by vanadium oxide species. The quantities of

esorbed NH3 were higher for all the samples containing vanadium
xide, reflecting a predominance of weak Lewis acid sites [50,51].
urves for (a) the bare zeolites, and (b) the impregnated zeolites.

3.2. Characterization of the vanadium oxide-impregnated zeolites

Quantitative phase analyses of the diffraction patterns for the
impregnated VA, VB, VC, and VD catalysts (Fig. S1) revealed small
quantities of crystalline V2O5 species. In terms of zeolite crys-
tallinity, the XRD patterns were similar to those for the bare
zeolites. In the treatment of the XRD data, the crystallography infor-

mation file (CIF) from the International Zeolite Association (IZA)
was adopted for the MFI  zeolite, while the 29140 standard from the
ICSD database was  used for V2O5. From comparison of the samples,
a crystalline V2O5 mass fraction of 9.0% was obtained for the parent



L.G. Possato et al. / Catalysis T

200 30 0 40 0 50 0

335 nm

373 nm

f(
R

) 
(a

rb
. u

ni
t)

Wavelenght  (n m)

VD
 VC
 VB
 VA

F

c
p
a
T
c
m
w
o
p
d

U
s
b
s
f
i
2
T
i
a
m
h
v
s
i
t

decomposition was  related to contact of the glycerol molecule and

F
3

ig. 5. UV–Vis diffuse reflectance spectra of samples containing vanadium oxide.

atalyst, which was very close to the 10% mass percentage used in
reparation of the samples, while V2O5 mass fractions between 4%
nd 6.5% were obtained for the desilicated and acid treated samples.
his effect of dispersion on the support, with production of poorly
rystallized V2O5 particles, could be attributed to the creation of
esopores and the capacity to cover the zeolite surface during the
et impregnation process. Comparison of the mesopore volumes

f the bare and impregnated zeolites (Table 1) confirmed the dis-
ersion of V2O5 in the mesopores. The important influence of V2O5
ispersion on catalytic activity is discussed below.

The diffuse reflectance spectroscopy measurements in the
V–Vis region (Fig. 5) showed distinct results for the impregnated

amples. The shapes of the spectra in this region were influenced
y the local structures of the vanadium atoms. For example, the
pectral range 333–500 nm provides information about the trans-
er of low energy electrons between O and V5+ for vanadium atoms
n octahedral coordination [52,53]. On the other hand, the range
85–333 nm is related to vanadium in tetrahedral coordination.
he green dashed rectangle highlighted in Fig. 5 indicates a region
nfluenced by the vanadium oxide environment. Bands at 335 nm
nd 373 nm were due to electron charge transfer of V5+ with ter-
inal or bridging oxygen anions, respectively. In other words, the

ighlighted region was  associated with terminal and supported
anadium oxides. The main peak occurred at 384 nm,  although

hifts to higher energy (or lower wavelength) could occur, depend-
ng on the degree of vanadium oxide coordination by water. Hence,
he systematic increase in intensity of this band complemented

             Glycerol dehy dration  

0 1 2 3 4 5 6
0

20

40

60

80

100

 A
 B
 C
 D
Al2O3

G
ly

ce
ro

l C
on

ve
rs

io
n 

(%
)

Time (h)

ig. 6. Glycerol dehydration and oxidehydration of samples without (left plot) and with
.0  mL/h and 6.0 mL/h of glycerol solution, respectively.
oday 289 (2017) 20–28 25

the previous finding of greater dispersion of V2O5 on the porous
zeolites.

3.3. Catalytic activity

3.3.1. Step 1 − glycerol dehydration
The glycerol dehydration reaction occurs in two sequen-

tial reactions. In the first reaction step, glycerol dehydrates on
acid sites, giving rise to a water molecule and a very reactive
3-hydroxypropene intermediate that rapidly isomerizes via a keto-
enol rearrangement to 3-hydroxypropanal. The 3-hydroxypropanal
molecule then dehydrates, releasing water and acrolein. This reac-
tion sequence occurs at protonic Brønsted acid sites [12,30,54]. In
contrast to the performance of the acid sites of the zeolites, a plot
obtained using a reference alumina (which mainly contained Lewis
acid sites) as catalyst reflected low levels of activity and stability in
the reaction (Fig. 6, Table 2).

The catalytic results obtained for samples A, B, C, and D are
summarized in Fig. 6. Regardless of the sample or the reaction
time, the main product of glycerol dehydration was  acrolein. Glyc-
erol conversions of 88% and 87% were achieved using sample A
and desilicated sample B, respectively. The beneficial effect of the
micro-mesoporosity of sample B was  shown by a decrease in cata-
lyst deactivation from 19% to 7%.

The acid treated samples (C and D) both showed glycerol con-
version exceeding 90% during the first hour of reaction. However,
there was more pronounced deactivation of the sample treated
with hydrochloric acid (sample D), with deactivation values of 5.2%
and 18.4% for samples C and D, respectively. These findings indi-
cated that both acids caused leaching of EFA (Table 1), and that
HCl was  less selective than oxalic acid, because it also removed
part of the structural aluminum, damaging the zeolite structure and
consequently affecting the activity of the catalyst in the reaction.

As mentioned before, all the samples were more selec-
tive to acrolein, compared to other reaction products such as
acetaldehyde, 3-hydroxypropanal, and acetol (Fig. 7). The prod-
uct distributions obtained for sample A after 1 and 6 h (Fig. S2)
were indicative of decreased selectivity to acetaldehyde (2 carbon
atoms) and increased selectivity to 3-hydroxypropanal (3 carbon
atoms). This suggested that decomposition of the primary molecule
occurred at the beginning of the reaction, and that this decomposi-
tion was associated with coke formation and COx release [30]. The
products with strong acid sites on the catalyst surface that became
progressively covered with coke, resulting in deactivation of the
strong acid sites. This was also reflected in the lower selectivity to

Glycerol oxidehydrati on 

0 1 2 3 4 5 6
0

20

40

60

80

100

 VA

Time (h )

 VB

G
ly

ce
ro

l C
on

ve
rs

io
n 

(%
)

 VC

 VA - 3 mL/h

 VD

 vanadium oxide (right plot). The filled and empty symbols correspond to flows of



26 L.G. Possato et al. / Catalysis Today 289 (2017) 20–28

Table  2
Reactant flow, conversion at time zero, catalyst deactivation, and %wt. of coke after 6 h on glycerol stream: (1) glycerol dehydration, and (2) glycerol oxidehydration.

Reaction Catalyst 10 wt.% glycerol
solution flow (mL/h)

Conversion at
time zero (%)

Catalyst
deactivation (%)

% wt.  of
coke

(1) A 3 90 19.4 12.6
B  89 7.0 15.5
C  100 5.2 17.8
D  100 18.4 14.1
Al2O3 65 68.5 55.5

(2)  V-A 6 100 42.4 (0.0)a 12.8 (4.7)
V-B  89 22.4 (0.0) 12.2
V-C  93 20.9 (0.0) 10.4
V-D  

a In brackets are indicated the results of catalyst deactivation under a flow of 3.0 mL/h 

0

10

20

30

40

50

60

 S
el

ec
. C

on
de

ns
. P

ro
du

c.
 (

%
)

A
 B
 C
 D

3-
hyd

ro
xy

pro
pan

al

Acr
ole

in

Acr
yli

c A
cid

Pro
pan

al

Ace
ta

ld
eh

yd
e

Ace
tic

 A
cid

Ace
to

l

Ally
l A

l.

Pro
pan

oic
 A

c.

Car
bon

 B
ala

nce
0

10

20

30

40

50

60

 S
el

ec
. C

on
de

ns
. P

ro
du

c.
 (

%
)

VA
 VB
 VC
 VD

Fig. 7. Selectivity towards condensable products and carbon balance in dehydration
(top) and oxidehydration (bottom) of the catalysts during 1 h of reaction at 300 ◦C
a ◦

a
u
i

g
t
g
e
t
l
s
s
o
m
z

ments applied to the samples (Fig. 7 and S3). Use of sample VA
resulted in 5% of acrylic acid after the first hour on stream, with
nd  350 C, respectively.

cetic acid after 6 h of reaction (Fig. S2), since acetic acid is a prod-
ct formed from acetaldehyde oxidation. Furthermore, and most

mportantly, there was increased selectivity to acrolein.
Different behavior was observed for samples B, C, and D, with

reater amounts of carbonaceous deposits detected, compared
o the parent zeolite, despite lower deactivation. The thermo-
ravimetric analyses of the spent catalysts (Fig. S3) enabled
stablishment of relationships between the mesopore volumes and
he amounts of carbonaceous compounds deposited on the cata-
ysts, based on the weight loss. In the case of the purely microporous
ample A, the coke was mainly deposited within straight and sinu-
oidal micropores, or in the entrances of pores, blocking the access
f new glycerol molecules. The effect of coke on catalytic perfor-

ance was more noticeable, even for low coke contents. In porous

eolites, the coke is preferentially located in the intra-crystalline
100 20.9 (0.0) 14.4

of glycerol solution.

pockets created by desilication with NaOH and acid leaching, main-
taining the micropores available for glycerol [24].

3.3.2. Steps 1 and 2 − glycerol oxidehydration
As mentioned before, the two steps of glycerol oxidehydration

are (i) the dehydration of glycerol to acrolein on acid sites [2,30],
and (ii) the conversion of acrolein to acrylic acid on redox sites [55].
Therefore, in the impregnated catalysts, the catalytic sites respon-
sible for glycerol dehydration were the Brønsted acid sites, while
V2O5 (better represented as V2O5-x) was  responsible for acrylic
acid formation. The V2O5 impregnation affected the acid sites of
the catalysts, increasing the contribution of the Lewis acid sites
and covering the strong Brønsted acid sites, as observed from the
TPD-NH3 analyses. As reported previously, the amount of impreg-
nated V2O5 significantly affected the proportions of acid and redox
sites, leading to substantial alterations in catalyst activity [26]. The
main difference between the two  groups of samples concerned cat-
alyst stability. No deactivation at all was  observed for the samples
impregnated with vanadium oxide. In order to be able to observe
the deactivation and compare samples B, C, and D,  the flow of glyc-
erol fed to the reactor was  increased from 3 to 6 mL/h (see VA results
in Fig. 6, open and closed symbols). This change enabled detection
of 42.4% deactivation of the VA catalyst. Despite the deactivation
under this new experimental condition, the presence of vanadium
oxide reduced the loss of catalytic activity, compared to the bare
zeolites, demonstrating the multifunctional characteristics of these
catalysts in promoting conversion, with selectivity to acrylic acid
and stability of catalytic activity over longer periods.

The desilicated and impregnated sample (VB) showed decreased
deactivation in the dehydration reaction, compared to the VA cat-
alyst, similar to the behavior observed for the bare zeolites. The
coke was  deposited in the formed mesopores, avoiding obstruction
of the micropores. In addition, the removal of EFA by the action of
oxalic acid, followed by impregnation (catalyst VC), resulted in a
further small reduction in deactivation, which decreased to 20.9%.

An interesting result was obtained for the sample treated with
hydrochloric acid and impregnated with V2O5 (sample VD). This
zeolite and the reference alumina showed the highest levels of
deactivation in the dehydration of glycerol. However, in the oxide-
hydration reaction, the VD catalyst presented deactivation very
close to that of the VC catalyst, because the action of vanadium
oxide helped to reduce coke formation by oxidizing smaller coke
molecules before oligomerization. Furthermore, the mesoporosity
helped in dispersing vanadium oxide on the surface of the zeolite,
as confirmed by the UV–vis analysis that showed an increase in the
signal at 335–373 nm.

The distribution of the products was  also affected by the treat-
selectivity to acrylic acid increasing to 25% after 6 h. These sam-
ples contained an average of 12 wt.% coke, so the shift in the acrylic



L.G. Possato et al. / Catalysis Today 289 (2017) 20–28 27

mpreg

a
d
s
n
i
p
i
t

a
c
g
C
h
l
6
s
t
e
w
t
t
a

a
f
t
v
t
m
i
i
o
s
z
n

a
v
p
o
t
a
[
s
t
p

Fig. 8. TG (a) and DTA (b) curves of the catalysts i

cid yield could be explained by the coverage by coke of the more
eactivating sites. It should be noted that the acrylic acid selectivity
howed a dependence on the glycerol flow. A flow of 3.0 mL/h was
ot only beneficial to catalyst stability, but also enabled selectiv-

ty to acrylic acid of 17% to be achieved in the first hour. Conditions
roviding greater selectivity could therefore be obtained by adjust-

ng the glycerol contact time. The initial acrylic acid selectivity of
he VB catalyst (14%) was higher than obtained for the VA sample.

Other products of glycerol oxidehydration are acetic acid and
cetaldehyde, which both arise from the bifunctional nature of the
atalyst. The acid sites crack the initial three carbon atoms of the
lycerol molecule, resulting in acetaldehyde and one molecule of
Ox. The presence of O2 then leads to the oxidation of acetalde-
yde to acetic acid. The selectivities to these two  products were

ower than 10% in the first hour of reaction, and decreased after
 h due to deactivation of the sites. This behavior was the oppo-
ite of that observed for the acrylic acid selectivity, suggesting that
he same sites were involved. The carbon balance between the glyc-
rol feed and the outflowing condensable liquid products increased
ith the glycerol flow and in the presence of V2O5. At glycerol solu-

ion flow rates of 3.0 mL/h (for the bare zeolites) and 6.0 mL/h (for
he impregnated samples), the average carbon balances were 30%
nd 55%, respectively.

The activity results showed that the mesopores in the catalysts
ssisted the mass transport of reactant and products, and there-
ore promoted the catalytic activity. In addition, the formation of
he extra porosity assisted in accommodation of the much less
olatile polymeric coke molecules, which remained deposited in
he intra-crystalline pockets within the zeolite mesopores, hence

aintaining access to the micropores. Two types of coke are formed
n glycerol reactions: (1) polyaromatic compounds formed in rad-
cal reactions, and (2) polyglycols formed by the condensation
f neighboring glycerol molecules [26]. Previous characterization
tudies [20–22] have shown that both types are present in bare
eolites, while the polyglycol type is suppressed following impreg-
ation with V2O5.

The results of the thermogravimetric analyses of the spent cat-
lysts are shown in Fig. 8. The DTA curves of the catalysts with
anadium oxide showed two exothermic peaks (Fig. 8b). The first
eak, at lower temperature (∼350 ◦C), was associated with the re-
xidation (exothermic event) of vanadium species (V4+ to V5+) in
he case of the spent V2O5/ZSM-5 catalysts [20]. The second peak, at
bout 500 ◦C, was due to polyaromatics (known as stubborn coke)
8,56,57]. In the first temperature region, some samples showed a

light increase in mass (Fig. 8a), associated with the oxidation of V4+

o V5+ (highlighted in Fig. 8b) [26]. The VD sample showed a small
eak near 200 ◦C, which could have been related to the decom-
nated with vanadium oxide after 6 h of reaction.

position of carbonaceous species on the catalyst surface. The high
porosity of this sample (Table 1) was likely to have contributed
to the oxidation of coke precursors at low temperatures. For com-
parison, the thermogram of the most coked sample A is present in
Fig. 8a . The largest DTA signal (Fig. 8b) represents the two species
of coke formed.

As mentioned, despite the Lewis acid sites are formed in large
amounts after V2O5 impregnation, condition that could damage
the catalytic activity as shown for �-Al2O3, the maintenance of
Brønsted acid sites with the coverage of the strong Brønsted acid
sites by the impregnation was an important aspect for maintaining
catalytic activity for a prolonged time.

4. Conclusions

The alkaline treatment of ZSM-5 zeolite with NaOH was  effec-
tive for obtaining a micro-mesoporous zeolite by partial disruption
of the crystalline framework due to silicon removal. A portion of the
framework aluminum atoms in tetrahedral coordination was also
removed, but due to their low solubility, these atoms remained
on the zeolite as EFA (extra-framework aluminum). The removal
of EFA was achieved by subsequent acid treatment using either
hydrochloric acid or oxalic acid. The latter was more effective,
because although hydrochloric acid acted to dissolve oligomeric
aluminum oxide species, it also attacked the crystalline zeolite
structure, while oxalic acid additionally acted as a chelating agent.
The micro-mesoporous zeolites were subsequently impregnated
with vanadyl sulfate solution and calcined to form supported V2O5.
Spectroscopic measurements in the UV–Vis region indicated that
V2O5 was well dispersed on the porous zeolites, due to the high
pore volumes. The dispersion of V2O5 increased the quantity of acid
sites on the zeolites. The beneficial effects of micro-mesoporosity
and V2O5 dispersion could be seen in the performance of the cat-
alysts during glycerol conversion. The selectivities to acrolein and
acrylic acid were enhanced, and the smaller amounts of coke led to
reduced deactivation.

Acknowledgements

This work was  supported by the Brazilian agencies CNPq

(grants 473456/2012-5 and 401679/2013-6) and FAPESP (grants
2013/10204-2, 2013/50023-7 and 2014/11952-5). The authors also
thank the Brazilian Synchrotron Light Laboratory (LNLS) in Camp-
inas for use of the XPD beamline (proposal XPD-17839).



2 lysis T

A

i
0

R

[

[

[

[
[

[

[
[

[

[

[

[

[

[

[
[

[

[

[

[

[

[

[

[

[

[
[

[

[
[

[

[
[

[

[

[
[

[

[
[
[
[

[
[
[

Dumeignil, Green Chem. 12 (2010) 1922–1925.
8 L.G. Possato et al. / Cata

ppendix A. Supplementary data

Supplementary data associated with this article can be found,
n the online version, at http://dx.doi.org/10.1016/j.cattod.2016.08.
05.

eferences

[1] B. Katryniok, S. Paul, V. Belliere-Baca, P. Rey, F. Dumeignil, Green Chem. 12
(2010) 2079–2098.

[2] B. Katryniok, S. Paul, F. Dumeignil, ACS Catal. 3 (2013) 1819–1834.
[3] C.A.G. Quispe, C.J.R. Coronado, J.A. Carvalho Jr., Renew. Sustainable Energy

Rev. 27 (2013) 475–493.
[4] M.A. Dasari, P.P. Kiatsimkul, W.R. Sutterlin, G.J. Suppes, Appl.Catal. A-Gen. 281

(2005) 225–231.
[5] T. Miyazawa, Y. Kusunoki, K. Kunimori, K. Tomishige, J. Catal. 240 (2006)

213–221.
[6] J. Chaminand, L. Djakovitch, P. Gallezot, P. Marion, C. Pinel, C. Rosier, Green

Chem. 6 (2004) 359–361.
[7] P.K. Vanama, A. Kumar, S.R. Ginjupalli, V.R.C. Komandur, Catal. Today 250

(2015) 226–238.
[8] H. Atia, U. Armbruster, A. Martin, J. Catal. 258 (2008) 71–82.
[9] F. Wang, J.-L. Dubois, W.  Ueda, Appl. Catal. A-Gen. 376 (2010) 25–32.
10] F. Cavani, S. Guidetti, L. Marinelli, M.  Piccinini, E. Ghedini, M.  Signoretto, Appl.

Catal. B-Environ. 100 (2010) 197–204.
11] N.R. Shiju, D.R. Brown, K. Wilson, G. Rothenberg, Top. Catal. 53 (2010)

1217–1223.
12] J. Deleplanque, J.L. Dubois, J.F. Devaux, W.  Ueda, Catal. Today 157 (2010)

351–358.
13] Y.T. Kim, K.-D. Jung, E.D. Park, Appl. Catal. A-Gen. 393 (2011) 275–287.
14] C.S. Carriç o, F.T. Cruz, M.B. Santos, D.S. Oliveira, H.O. Pastore, H.M.C. Andrade,

A.J.S. Mascarenhas, J. Catal. 334 (2016) 34–41.
15] W.Y. Pan, L. Huang, F. Qin, Y. Zhuang, X.M. Li, J.X. Ma,  W.  Shen, H.L. Xu, Acta

Phys. Chim. Sin. 31 (2015) 965–972.
16] J.P. Lourenco, M.I. Macedo, A. Fernandes, Catal. Commun. 19 (2012) 105–109.
17] J.A. Cecilia, C. Garcia-Sancho, J.M. Merida-Robles, J.S. González, R.

Moreno-Tost, P. Maireles-Torres, Appl. Catal. A-Gen. 516 (2016) 30–40.
18] A.S. Paula, L.G. Possato, D.R. Ratero, J. Contro, K. Keinan-Adamsky, R.R. Soares,

G.  Goobes, L. Martins, J.G. Nery, Microporous Mesoporous Mater. 232 (2016)
151–160.

19] L. Shen, H. Yin, A. Wang, Y. Feng, Y. Shen, Z. Wu,  T. Jiang, Chem. Eng. J. 180
(2012) 277–283.

20] L. Shen, H. Yin, A. Wang, X. Lu, C. Zhang, F. Chen, Y. Wang, H. Chen, J. Ind. Eng.
Chem. 20 (2014) 759–766.

21] M.  Dolores Soriano, P. Concepcion, J.M. Lopez Nieto, F. Cavani, S. Guidetti, C.
Trevisanut, Green Chem. 13 (2011) 2954–2962.

22] A. Chieregato, F. Basile, P. Concepcion, S. Guidetti, G. Liosi, M. Dolores Soriano,
C.  Trevisanut, F. Cavani, J.M. Lopez Nietoc, Catal. Today 197 (2012) 58–65.

23] A. Chieregato, M.  Dolores Soriano, F. Basile, G. Liosi, S. Zamora, P. Concepcion,

F.  Cavani, J.M. Lopez Nieto, Appl. Catal. B-Environ. 150 (2014) 37–46.

24] L. Shen, H. Yin, A. Wang, X. Lu, C. Zhang, Chem. Eng. J. 244 (2014) 168–177.
25] A. Chieregato, M.D. Soriano, E. Garcia-Gonzalez, G. Puglia, F. Basile, P.

Concepcion, C. Bandinelli, J.M.L. Nieto, F. Cavani, ChemSusChem 8 (2015)
398–406.

[

[
[

oday 289 (2017) 20–28

26] L.G. Possato, W.H. Cassinelli, T. Garetto, S.H. Pulcinelli, C.V. Santilli, L. Martins,
Appl. Catal. A: Gen. 492 (2015) 243–251.

27] L.H. Vieira, K.T. Carvalho, E.A. Urquieta-González, S.H. Pulcinelli, C.V. Santilli,
L.  Martins, J. Mol. Catal. A: Chem. (2015), http://dx.doi.org/10.1016/j.molcata.
2015.12.019 (in press).

28] M.V. Rodrigues, C. Vignatti, T. Garetto, S.H. Pulcinelli, C.V. Santilli, L. Martins,
Appl. Catal. A: Gen. 495 (2015) 84–91.

29] H. Decolatti, B. Dalla Costa, C. Querini, Microporous Mesoporous Mat. 204
(2015) 180–189.

30] L.G. Possato, R.N. Diniz, T. Garetto, S.H. Pulcinelli, C.V. Santilli, L. Martins, J.
Catal. 300 (2013) 102–112.

31] J.C. Groen, J.C. Jansen, J.A. Moulijn, J. Perez-Ramirez, J. Phys. Chem. B 108
(2004) 13062–13065.

32] J.C. Groen, L.A.A. Peffer, J.A. Moulijn, J. Perez-Ramirez, Microporous
Mesoporous Mat. 69 (2004) 29–34.

33] J.C. Groen, T. Bach, U. Ziese, A. Donk, K.P. de Jong, J.A. Moulijn, J.
Perez-Ramirez, J. Am.  Chem. Soc. 127 (2005) 10792–10793.

34] J.C. Groen, L.A.A. Peffer, J.A. Moulijn, J. Perez-Ramirez, Chem. A Eur. J. 11
(2005) 4983–4994.

35] J.C. Groen, J.A. Moulijn, J. Perez-Ramirez, J. Mater. Chem. 16 (2006) 2121–2131.
36] J.C. Groen, W.  Zhu, S. Brouwer, S.J. Huynink, F. Kapteijn, J.A. Moulijn, J.

Perez-Ramirez, J. Am.  Chem. Soc. 129 (2007) 355–360.
37] J. Perez-Ramirez, C.H. Christensen, K. Egeblad, C.H. Christensen, J.C. Groen,

Chem. Soc. Rev. 37 (2008) 2530–2542.
38] P. Mars, D.W. Van Krevelen, Chem. Eng. Sci. 3 (1954) 41–59.
39] D. Verboekend, S. Mitchell, M.  Milina, J.C. Groen, J. Perez-Ramirez, J. Phys.

Chem. C 115 (2011) 14193–14203.
40] H. Canova, A. Fontoura, R. Neuenschwander, B. Diaz, C. Rodella, Upgrades to

the XRD1 beamline optics and endstation at the LNLS, J. Phys. Conf. Series IOP
Publ. (2014) (p. 012004).

41] B. Toby, J. Appl. Crystallogr. 34 (2001) 210–213.
42] A.F. Gualtieri, S. Ferrari, M.  Leoni, G. Grathoff, R. Hugo, M.  Shatnawi, G. Paglia,

S.  Billinge, J. Appl. Crystallogr. 41 (2008) 402–415.
43] V. Paixao, R. Monteiro, M. Andrade, A. Fernandes, J. Rocha, A.P. Carvalho, A.

Martins, Appl. Catal. A-Gen. 402 (2011) 59–68.
44] R. Giudici, H.W. Kouwenhoven, R. Prins, Appl. Catal. A-Gen. 203 (2000)

101–110.
45] J.T. Smith, S. Bailey, Acta Crystallogr. 16 (1963) 801–811.
46] Z.M. Yan, M.A. Ding, J.Q. Zhuang, X.C. Liu, X.M. Liu, X.W. Han, X.H. Bao, F.X.

Chang, L. Xu, Z.M. Liu, J. Mol. Catal. A-Chem. 194 (2003) 153–167.
47] M.R. Apelian, A.S. Fung, G.J. Kennedy, T.F. Degnan, J. Phys. Chem. 100 (1996)

16577–16583.
48] S. Storck, H. Bretinger, W.F. Maier, Appl. Catal. A-Gen. 174 (1998) 137–146.
49] A.W. Chester, E.G. Derouane, Zeolite Charact. Catal. A Tutorial (2009).
50] M.  Petras, B. Wichterlova, J. Phys. Chem. 96 (1992) 1805–1809.
51] S.S.R. Putluru, A. Riisager, R. Fehrmann, Appl. Catal. B-Environ. 97 (2010)

333–339.
52] X.T. Gao, I.E. Wachs, J. Phys. Chem. B 104 (2000) 1261–1268.
53] L.J. Burcham, G. Deo, X.T. Gao, I.E. Wachs, Top. Catal. 11 (2000) 85–100.
54] B. Katryniok, S. Paul, M.  Capron, C. Lancelot, V. Belliere-Baca, P. Rey, F.
55] D. Vitry, Y. Morikawa, J.L. Dubois, W.  Ueda, Appl. Catal. A-Gen. 251 (2003)
411–424.

56] C.-J. Jia, Y. Liu, W.  Schmidt, A.-H. Lu, F. Schueth, J. Catal. 269 (2010) 71–79.
57] Y.T. Kim, K.-D. Jung, E.D. Park, Appl. Catal. B-Environ. 107 (2011) 177–187.

http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://dx.doi.org/10.1016/j.cattod.2016.08.005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0005
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0010
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0015
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0020
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0025
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0030
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0035
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0040
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0045
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0050
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0055
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0060
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0065
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0070
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0075
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0080
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0085
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0090
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0095
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0100
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0105
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0110
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0115
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0120
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0125
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0130
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
dx.doi.org/10.1016/j.molcata.2015.12.019
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0140
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0145
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0150
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0155
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0160
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0165
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0170
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0175
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0180
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0185
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0190
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0195
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0200
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0205
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0210
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0215
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0220
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0225
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevier.com/S0920-5861(16)30510-7/sbref0230
http://refhub.elsevie