Electrochemical Reduction of Cyanides at Metallic Cathodes: A Comparison with Biological HCN Reduction

Abstract

The electrochemical reduction of cyanides has been studied at a number of cathodes both in near-neutral and in alkaline solutions. Nickel appears as the most effective cathode material, promoting cyanide reduction with current efficiencies close to 70%, even in moderately alkaline solutions. In all cases, the eletroreduction of cyanides leads to a mixture of (methylamine) and products (methane and ammonia). The use of Nafion films loaded with Ni microparticles enabled us to markedly increase the effective current densities for cyanide reduction. The electrochemical reduction of is shown to present interesting similarities and differences with the biological cyanide reduction process. © 2001 The Electrochemical Society. All rights reserved.