CoSe nanoparticles prepared by the microwave-assisted polyol method as an alcohol and formic acid tolerant oxygen reduction catalyst

CoSe catalyst supported on nanoporous carbon was synthesized by microwave heating of glycerol solutions of Co(II) acetate and sodium selenite. The electrocatalytic behavior of the CoSe/C for oxygen reduction reaction (ORR) and its tolerance to several alcohols and formic acid were investigated by rotating disk electrode voltammetry and the results were compared with those of Pt/C. The results indicate that CoSe/C is a highly selective electrocatalyst towards ORR and shows a very high degree of tolerance to the presence of formic acid, methanol, ethanol, 2-propanol and ethylene glycol in acid medium. For a 20 wt.% CoSe/C, the onset potential and the magnitude of the current for ORR were almost the same with or without the presence of these fuels. In contrast, the Pt/C catalyst exhibited a mixed potential due to the simultaneous oxidation of the fuels and reduction of oxygen, which in turn caused the onset potential for the ORR to shift cathodically by ca. 500 mV in the presence of these fuels. Electrochemical measurements showed that the synthesized CoSe/C catalyst had a four-electron transfer mechanism for ORR. It is expected that this low cost electrocatalyst with its almost full tolerance and multi-fuel capability can find application in conventional and mixed-reactant fuel cells fueled with low molecular weight alcohols or formic acid.