One-pot synthesis of PdM/RGO (M=Co, Ni, or Cu) catalysts under the existence of PEG for electro-oxidation of methanol

Abstract

The binary PdM (M=Co, Ni, Cu) catalysts were synthesized with one-pot on reduced graphene oxide (RGO) using the sodium borohydride reduction method under the existence of the polyethylene glycol (PEG). And the catalysts were used for the electro-oxidation of methanol in alkaline media. Cyclic voltammetry (CV) and chronoamperometry (i-t) tests indicated that the Pd-based binary systems significantly enhanced electrochemical activities and improved stability compared with the monometallic Pd/RGO and commercial Pd/C (JM) catalysts. The lower onset potentials of PdM/RGO indicated that the prepared PdM/RGO catalysts had the better electrochemical performance than Pd/RGO and Pd/C (JM). Physicochemical properties of the PdM/RGO catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman. These results show that the better electrochemical performance of PdM/RGO can be ascribed to the addition of the second metal and PEG, because M successfully modified the morphology and electronic structure of Pd, and improved dispersibility of PdM on the reduced graphene oxide. And these modifications can be easily carried out under the presence of PEG.