Electrocatalysis of Pd–Er bimetallic catalysts for methanol oxidation in alkaline media

The Pd–Er/C catalysts with different Pd/Er ratios were synthesized through a simple simultaneous reduction reaction with sodium borohydride in aqueous solution. The structural and morphological features were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The electrocatalytic performance of those catalysts for methanol oxidation in alkaline media was tested using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). It is found that the Pd-4Er/C catalyst has a higher catalytic activity than the Pd/C catalyst. CO stripping experiments show its good resistance to CO poisoning, which can be explained by a bifunctional mechanism. According to the results from the X-ray photoelectron spectroscopy (XPS), the higher content of metallic Pd caused by the doping of metal Er also accounts for the improvement of catalytic performance. This work provides a highly efficient catalyst for methanol electrooxidation in alkaline media.