Preparation And Research On Carbon Supported Pd-based Binary Alloys Catalytics And Electro-catalytic

Direct methanol fuel cell (DMFC) is concerned as one of the most promising green power sources due to the convenient transportation and storage and the high energy efficiency of methanol fuel. Noble metal Pt or Pt- alloy catalysts have been widely used as anodic catalysts in DMFC, but the high cost limites its commercial applications.In this paper, the carbon supported M(M=Pt?Pd) catalysts were prepared by sol-gel method. The composition, morphology and structure catalysts were characterized by TEM, XRD and XPS, respectively. The activities of catalysts were measured by cyclic voltammetry (CV) methods. Pt/C catalyst was regarded as a standard to evaluate other catalysts for methanol electro-oxidation. The results indicated that the particles of Pt and Pd catalysts are Fcc nanocrystals and evenly distribute on carbon, with 3nm?10nm particle size. According to the CV results, the current density on Pd/C catalyst is 890mA/mg in lmol/L CH3OH+1mol/L NaOH solution, initial oxidation potential is -0.85V. Under the same conditions, the current density on Pt/C catalyst is 1348mA/mg, which is 66% of that of Pt/C catalyst. The initial oxidation potential is -0.9V,50mV higher than that of Pd/C catalyst. Therofore, the carbon-supported palladium catalyst exhibited good catalytic activity for methanol electro-oxidation. Furthermore, due to the low cost, the Pt/C catalyst can be as a great potential substitute for traditional nobel metal.The palladium-based binary alloy Pd-Ni, Pd-Ag, Pd-Ru, Pd-W and Pd-Co catalysts were prepared by sol-gel method. The activities of catalysts for methanol electro-oxidation were studied by CV methods. The results showed that the current density on Pd1W1?Pd1Ru1? Pd1Ag1?Pd1Ni1 and Pd1Co1 catalyst is 422.1mA/mg,263.2mA/mg,203.7mA/mg, 195.8mA/mg and 143mA/mg in lmol/L CH30H+lmol/L NaOH solution, respectively. In the same alkaline media, the order of the activities of the binary alloy is Pd1W1>Pd1Ru1>Pd1Ag1>Pd1Ni1>Pd1Co1. It is concluded that the palladium-based binary alloy exhibited good catalytic activity for the methanol electro-oxidation. The activities of Pd-W and Pd-Ru catalysts are the highest, followed by Pd-Ag?Pd-Ni?Pd-Co catalysts.