Reaction analysis of ethanol electro-oxidation on PdRu/C catalyst at intermediate temperature

Abstract

To evaluate the availability of non-Pt catalysts in a direct ethanol fuel cell operating at an intermediate temperature, a PdRu/C catalyst was synthesized by a liquid phase reduction method and its catalytic activity for ethanol electrooxidation was investigated at approximately 250°C using a single cell fabricated with CsH2PO4 proton-conducting solid electrolyte. Electrochemical measurement and reaction product analysis revealed that direct electro-oxidation of ethanol and hydrogen production from ethanol proceeded in parallel on PdRu/C. The PdRu/C catalyst showed high activity for hydrogen production reaction comparable to that on the PtRu/C catalyst, which results in high current density at low electrode potentials (<200 mV). C-C bond dissociation proceeded rapidly on the PdRu/C catalyst, while the subsequent oxidation of the adsorbed C1 species may be the rate-determining step at the intermediate temperature. For further activation of the PdRu/C catalyst, activation of surface OH should be investigated. © 2014 The Society of Chemical Engineers, Japan.