High Methanol Tolerance of PdCo/C Catalysts for Oxygen Reduction

摘要

A PdCo/C catalyst was prepared by an organic colloid method using citrate as complexing agent, ethylene glycol (EG) as reducing agent and solvent. And the nanocomposition was characterized by X-ray diffraction (XRD) and energy dispersive X-ray spec-troscopy (EDX). XRD patterns showed Pd particles had a face-centered cubic crystal structure and small particle size. It was found that the Pd - Pd distance decreased by the addition of Co, indicating the formation of Pd-Co alloy. The electrocatalytic activities were evaluated by oxygen reduction, which was executed with cyclic voltammetric method with a rotating disk electrode system. The Pd-Co/C catalysts showed higher catalytic activities than Pd/C catalysts and, better methanol tolerance than Pt/C (Johnson-Matthey) for the oxygen reduction. The results implied that the Pd-Co/C catalyst might be a good potential cathodic catalyst for direct methanol membrane fuel cell (DMFC).