Inverse effects of supporting electrolytes on the electrocatalytic nitrate reduction activities in a PtNafionPt-Cu-type reactor assembly

Abstract

In this article, the effects of Cl- and SO42- ions on the electrocatalytic nitrate reduction activities in a sandwich-type reactor assembly are illustrated. It was noticed that a PtNafionPt-Cu assembly offers its best efficiency in the absence of any supporting electrolytes. The Pt-Cu thin layers adsorb chloride and sulphate ions firmly, and this adsorption blocks the H+ reducing sites at the cathode end of the catalytic assembly, leading to a decrease in catalytic efficiency. In the presence of chloride and sulphate ions, the reduction reactions of NO3- and NO2-, respectively, are relatively favoured.