Methanol oxidation on PdRh/C electrocatalyst in alkaline media: Temperature and methanol concentration dependencies

PdRh/C is a highly active electrocatalyst for methanol oxidation reaction in alkaline media. In this study, the methanol oxidation at PdRh/C was investigated electrochemically in half-cell experiments for various temperatures and various methanol concentrations in the electrolyte. The results obtained by these measurements were compared to the ones of Pd/C. Thus, new insights on how Rh influences the electrocatalytic activity of Pd were found. The apparent activation energies calculated from potentiostatic and potentiodynamic measurements show that the apparent activation energy of the methanol oxidation reaction on Rh-modified electrocatalysts is significantly lower than for Pd/C, which is attributed to the enhancement of COads oxidation on PdRh/C due to the oxophilic character of Rh.