Quaternary Pt 2 Ru 1 Fe 1 M 1 /C (M=Ni, Mo, or W) catalysts for methanol electro-oxidation reaction

Quaternary Pt 2 Ru 1 Fe 1 Ni 1 /C (M=Ni, Mo, or W) catalysts were investigated for the methanol electro-oxidation reaction (MOR). Electrocatalytic activities of the quaternary catalysts for CO electro-oxidation were studied via CO stripping experiments, and the Pt 2 Ru 1 Fe 1 Ni 1 /C and Pt 2 Ru 1 Fe 1 W 1 /C catalysts exhibited lowered on-set potential compared to that of a commercial PtRu/C catalyst. MOR activities of the quaternary catalysts were determined by linear sweep voltammetry (LSV) experiments, and the Pt 2 Ru 1 Fe 1 Ni 1 /C catalyst outperformed the commercial PtRu/C catalyst by 170 and 150% for the mass and specific activities, respectively. X-ray photoelectron spectroscopy (XPS) was employed to analyze surface oxidation states of constituent atoms, and it was identified that the structure of the synthesized catalysts are close to a nano-composite of Pt and constituent metal hydroxides and oxides. In addition, the XPS results suggested that the bi-functional mechanism accounts for the improved performance of the Pt 2 Ru 1 Fe 1 Ni 1 /C and Pt 2 Ru 1 Fe 1 W 1 /C catalysts.