Preparation And Electrochemical Performance Research Of Pemfc Metal Oxides-Doped Platinum Core Shell Catalyst

Proton exchange membrane fuel cell (PEMFC) has been considered as the most promising new green energy with its high power density and abundant fuel source in the21st century. As one of the key components of PEMFC, catalyst is important for the development and commercialization of PEMFC. At present, the precious metal platinum as the main active component of catalyst was researched more widely. However, Pt hampers the commercial process of fuel cells with its high price and the low electrocatalytic activity. Therefore, the study of low load platinum and high-performance platinum catalyst is important for the development and widely application of PEMFC.In this paper, Ag@Pt/MWCNTs-MnO2、Ag@Pt/MWCNTs-CeO2and Ag@Pt/MWCNTs-TiO2were prepared and using various characterizations to measure the electrocatalysts to prepare the PEMFC cathode catalyst with high Pt utilization and low cost. More details are presented as following:(1) Synthesis and electrocatalytic performance of MnO2doped Ag@Pt/MWCNTsAg@Pt/MWCNTs core shell catalyst were synthesized by a two-step method with MWCNTs support. Then α-MnO2and β-MnO2were synthesized by a hydrothermal method, and MnO2-doped Ag@Pt/MWCNTs composites were prepared by ultrasonic treatment for oxygen reduction reaction. The largest electrochemical active area Ag10%@Pt10%/MWCNTs-20%a-MnO2is85.83m2·g-1, Ag10%@Pt10%/MWCNTs-20%-β-MnO2is68.83m2·g-1which increase significantly relative Johnson Matthey20%Pt/C catalysts (51.59m2·g-1)(2) Synthesis and electrocatalytic performance of CeO2doped Ag@Pt/MWCNTsCeO2was synthesized by a hydrothermal method by contraling the reaction condition. A variety of characterization methods prove the formation of CeO2and electrochemical characterization results imply the optimum doping amount of CeO2is20%。 The calculated values of the electrons transferred is3.7indicating that CeO2has the most efficient promoted catalytic effect to ORR. (3) Synthesis and electrocatalytic performance of TiO2doped Ag@Pt/MWCNTsTiO2was synthesized by a Sol-gel method and XRD shows that this article TiO2was anatase structure. Then the Ag@Pt/MWCNTs-TiO2composites were prepared by ultrasonic treatment. The electrocatalytic performance was evaluated by cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The largest electrochemical active area Ag10%@Pt10%/MWCNTs-15%TiO2is76.63m2· gl which is1.16times as much as that of10%Ag@10%Pt/MWCNTs.