用于质子交换膜燃料电池抗CO的Pt-CeO_2/C催化剂的制备和表征

Preparation and Characterization of CO Tolerance Pt-CeO_2/C Catalyst for Proton Exchange Membrane Fuel Cells

采用一步沉淀法,制备了纳米级Pt-CeO2/C电催化剂.透射电镜和X射线衍射表征结果表明,制备的催化剂Pt颗粒均匀分散于碳载体表面,其粒径主要分布于1.5～2.5nm.将Pt-CeO2/C催化剂制备成质子交换膜燃料电池膜电极,经循环伏安和单电池极化曲线测试发现,Pt-CeO2/C催化剂性能与Pt/C催化剂的相当.一氧化碳消除伏安测试和单电池的抗一氧化碳性能测试结果表明,Pt-CeO2/C催化剂具有很好的抗一氧化碳氧化性能.

The nano-scale Pt-CeO2/C catalyst was prepared by the co-precipitation method.The results of transmission electron microscopy and X-ray diffraction analysis show that the average size of Pt-CeO2/C noble metal particles （1.5～2.5 nm） is highly dispersed on the carbon supports.Pt-CeO2/C and a commercial Pt/C catalyst from Johnson Matthey Company were investigated by cyclic voltammetry and CO-stripping experiment.The cyclic voltammetry test shows that the Pt-CeO2/C catalyst has similar electrochemical surface area to Pt/C,which indicates that the home-made Pt-CeO2/C catalyst has high electrocatalytic activity for hydrogen oxidation.From the CO-stripping experiment,the Pt-CeO2/C catalyst showed very high CO tolerant activity compared to the Pt/C catalyst.We also fabricated the membrane electrode assembly with Pt-CeO2/C or Pt/C catalyst on the anode （the cathode also used the Pt/C catalyst） and found that Pt-CeO2/C catalyst showed higher performance than Pt/C catalyst.A tentative mechanism was proposed for a possible role of Ce as a co-catalyst in the Pt/C system for CO electrooxidation.