Activation of a Pt-based alloy by a Keggin-type cesium salt of heteropolytungstate towards electrochemical oxidation of ethylene glycol in acidic medium

This work reports the preparation and electrochemical characterization of PtSn/C and PtRh/C modified with a cesium salt of phosphotungstic acid, CsPTA, for use as electrochemical oxidation catalysts in acidic medium. The primary test system is the oxidation of ethylene glycol. Electrode with these modified nanoparticles confined as surface layers are used in studies not only on ethylene glycol but also on all side products of its oxidation in H2SO4 electrolyte. The experimental results reveal that films on carbon electrodes of nanoparticulate PtSn/C and PtRh/C modified with CsPTA enhance the catalytic activity relative to those lacking the CsPTA towards ethylene glycol oxidation. Higher anodic current densities are especially evident at low potentials, particularly below 0.35 V (vs. RHE). Additionally, a preliminary single fuel cell test with the CsPTA-modified PtSn/Vulcan anode shows a better performance than does the PtSn/Vulcan catalyst.