Comparison of methanol and ethylene glycol oxidation by alloy and Core-Shell platinum based catalysts

摘要

Two Core-Shell, Rucore-Ptshell and IrNiCore-PtRushell. XC72-supported catalyst were synthesized in a two-step deposition process with NaBH4 as reducing agent. The structure and composition of the Core-Shell catalysts were determined by EDS, XPS and XRD. Electrochemical characterization was performed with the use of cyclic voltammetry. Methanol and ethylene glycol oxidation activities of the Core-Shell catalysts (in terms of surface and mass activities) were studied at 80 C and compared to those of a commercial Pt-Ru alloy catalyst. The surface activity of the alloy based catalyst, in the case of methanol oxidation, was found to be superior as a result of optimized surface Pt:Ru composition. However, the mass activity of the PtRu/IrNi/XC72 was higher than that of the alloy based catalyst by -50%. Regarding ethylene glycol oxidation, while the surface activity of the alloy based catalyst was slightly higher than that of the Pt/Ru/XC72 catalyst, the latter showed ~66% higher activities in terms of Ag~1 of Pt. These results show the potential of Core-Shell catalysts for reducing the cost of catalysts for DMFC and DEGFC