PtSnCo/C Anode Catalyst for Methanol Oxidation

A binary metallic catalyst(PtSn/C) and a ternary metallic catalyst(PtSnCo/C) with a metal mass fraction of 20% were prepared by borohydride reduction and subsequent hydrothermal treatment in a glycol liquid phase.The structure and composition of the as-prepared electrocatalysts were characterized by X-ray diffraction(XRD) and energy-dispersive spectrometry(EDS).Their activity and stability for the catalysis of methanol oxidation were evaluated by anodic linear sweep voltammetry(LSV),cyclic voltammetry(CV),and the anodic stripping of a pre-adsorbed CO monolayer.We found that the PtSnCo/C catalyst gave the best catalytic activity for the methanol oxidation of all the catalysts including the commercial JM-PtRu/C catalyst.After 100 cycles,the peak current of methanol oxidation for the PtSn/C catalyst rapidly decreased to 11% of its initial peak current but PtSnCo/C decreased to only 50%.This result suggests that the PtSnCo/C catalyst has better chemical stability for the catalysis of methanol oxidation compared to the PtSn/C catalyst.The more negative onset potential of methanol oxidation for the PtSnCo/C catalyst relative to pre-adsorbed CO oxidation implies that the intermediates of methanol oxidation on the PtSnCo/C catalyst may be ones,which can be more easily oxidized than CO,instead of CO.