Study On The Pd-based Catalysts For Proton Exchange Membrane Fuel Cells

ABSTRACT: The dissertation summarize the development background, the working mechanism, characteristics and the classification. The brief history, working principle and problems of PEMCF are introduced briefly. The preparation methods and research situation of of the catalyst of PEMFC are introduced in details. In the paper, there are two explorations for Pd-based catalysts:First, alloy catalysts were studied. Carbon-supported Pd-Fe alloy catalysts were prepared by impregnation-reduction method using formaldehyde as the reductive. The Pd-Fe alloy catalysts were characterized by TEM, XRD and CV and compared to Pd/activated carbon. The Pd/C catalyst was improved by containing Fe and the Pd-Fe alloy catalysts in which molar ratio of Pd to Fe is 1 :1 have best catalytic activity. Fe was amorphous. The results of XRD infraction indicated that in the Pd-Fe alloy catalysts the stalline of Pd have changed when molar ratio of Pd to Fe is 1 :2.Second, the Pd-based metal oxide catalysts were studied. In research, CeO₂/C was prepared and then Pd-CeO₂/C catalysts were prepared. Pd-CeO₂/C catalysts were characterized by XRD, TEM and CV. The result indicated that The Pd/C catalyst was improved by containing CeO₂ for H₂ and CHOOH. The CeO₂/C particles distributed homogeneously and the particle size was less than 5 nm. The CeO₂/C was an ideal support. Exploring research was studied about Pd-MnO_x/C, but there are some problems which are solved by further research.