On the Influence of Ag on Pd-based Electrocatalyst for Methanol Oxidation in Alkaline Media: A Comparative Differential Electrochemical Mass Spectrometry Study

By Jurzinsky, Tilman; Cremers, Carsten; Pinkwart, Karsten; T
Published in Electrochimica Acta NULL 2016

Abstract

Abstract In this study methanol oxidation in alkaline media was investigated in detail on Pd/C, Ag/C and PdAg/C catalysts. The electrochemical activity towards methanol oxidation reaction, the surface inhibition behavior and the {CO2} current efficiency was evaluated for the catalysts by cyclic voltammetry, chronoamperometry, {CO} adsorbate stripping and {CH3OH} adsorbate stripping experiments in a differential electrochemical mass spectrometry (DEMS) flow cell setup. PdAg/C catalysts showed higher current densities, lower oxidation onset potentials and lower sensitivity to surface inhibition than Pd/C. Due to detailed studies on the {CO2} current efficiencies, side products and adsorbate reactions via DEMS, novel insights into the electrooxidation of methanol on Pd/C and PdAg/C were provided. Even though Ag/C itself was not significantly active for methanol electrooxidation, it was able to promote Pd in its electrochemical activity towards methanol oxidation reaction and selectivity towards production of CO2. Additionally, PdAg/C showed lower sensitivity to catalyst poisoning compared to Pd/C.

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