Carbon-supported PdSn-SnO_2 catalyst for ethanol electro-oxidation in alkaline media

摘要

Carbon-supported PdSn-SnO_2 with high electrical catalytic activity for ethanol oxidation in alkaline solution was synthesized using an impregnation reduction method. XRD analysis of the as-prepared PdSn-SnO_2/C revealed that the Pd diffraction peaks shifted to lower 2θ values with respect to the corresponding peaks of the Pd/C catalyst, indicating that Sn doping could shrink the Pd crystalline lattice. XPS measurements confirmed the existence of Sn and SnO_2 in the PdSn-SnO_2/C catalysts. The prepared PdSn-SnO_2/C catalysts presented a remarkably higher electrocatalytic activity than that of the Pd-Sn/C and Pd/C catalysts. This was mainly because the easy adsorption-dissociation of OH_(ads) over the SnO_2 surface changed the electronic effect and accelerated the adsorption of ethanol on the surface of Pd, thus enhancing the overall ethanol oxidation kinetics and contributing to a significant improvement in the catalytic activity.