A novel Rh–Ir electrocatalyst for the oxygen reduction reaction and the hydrogen and methanol oxidation reactions

Abstract

A novel Rh–Ir based material was synthesized by pyrolysis of an Ir4(CO)12/Rh6(CO)16 mixture in a reductive (H2) atmosphere. The material was characterized by FTIR spectroscopy, X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy, and was evaluated as electrocatalyst for oxygen reduction and hydrogen and methanol oxidation by rotating disk electrode measurements. The bimetallic material shows a high catalytic activity for the oxygen reduction reaction and is also capable to carry out the hydrogen oxidation reaction even in the presence of carbon monoxide in different concentrations (100 ppm and 0.5%), in contrast with commercial platinum catalysts, which become easily deactivated by CO. The activity of the catalyst for methanol oxidation is acceptable but still low in comparison with Pt–Ru. The results show that the new bimetallic catalyst is a potential candidate to be evaluated as both cathode and anode in a reforming hydrogen PEMFC, and as an anode in a direct methanol fuel cell.