LAUSR

Abstract Two new catalysts for the electrochemical Fenton process: Sn2+, and Bi3+ cations have been investigated. We refer to them as "two-electron" catalysts because they are expected to be oxidized to Sn4+ and Bi5+ cations respectively in the reaction with hydrogen peroxide generated in the cathodic reaction. In comparison, the classical catalyst for the electro-Fenton process, Fe2+ cations, are oxidized to Fe3+ cations, thus we call it a "one-electron" catalyst. Decolorization efficiency for two dyes of different types: triarylmethane dye Bromocresol Green and azo-dye Metanil Yellow has been investigated in the case of new catalysts and Fe2+ for comparison. The novel, two-electron catalysts lead to better decolorization efficiency in the degradation of azo-dye Metanil Yellow in comparison to Fe2+ cations.