Electrochemical decomposition of cyanides on tin dioxide electrodes in alkaline media
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Data
1996-04-01
Autores
Fugivara, Cecilio Sadao [UNESP]
Sumodjo, PTA
Cardoso, Arnaldo Alves [UNESP]
Benedetti, Assis Vicente [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Royal Soc Chemistry
Resumo
The electrochemical oxidation of cyanide in alkaline media was studied at different pH levels on SnO2 doped with Sb supported on titanium, at 25 degrees C, the electrooxidation of CN- at constant current follows a first-order rate law with a half life of t(1/2) = 35 min on SnO2-SbOx electrodes and t(1/2) = 69 min on SnO2-SbOx-RuO2 electrodes, in K2SO4(aq), pH 12, the reaction rate increases with the applied current and tends to reach a plateau when j > 20 mA cm(-2), In the pH range 10-13.5 the reaction rate diminishes as pH is increased owing to an increasing competition between CN- and OH- ions for the electrode surface. Addition of chloride to the solution does not alter the rate law but increases the reaction rate, A mechanism is proposed to explain the observed behaviour.
Descrição
Palavras-chave
cyanide electrooxidation, tin dioxide doped electrodes, kinetic study of cyanide oxidation
Como citar
Analyst. Cambridge: Royal Soc Chemistry, v. 121, n. 4, p. 541-545, 1996.