无机胶体法制备Pt/C催化剂及其性能表征

Preparation by Inorganic Colloid Method and Characterization of Pt/C Catalysts

采用无机胶体法制备用于质子交换膜燃料电池(PEMFC)的Pt/C催化剂。研究了影响PtO2胶体生成和稳定性的因素(溶液的pH值、浓度和温度条件等)以及不同还原剂浓度对Pt/C催化剂性能的影响。透射电子显微镜测试结果表明,采用经优化的工艺条件所制备的Pt/C催化剂平均粒径为3nm,且分散性好、粒度均匀。X-射线衍射分析表明,催化剂中Pt(111)晶面的相对含量较高,有利于加速氧还原反应。单体PEMFC的电压/电流密度曲线测试表明,所制备的Pt/C催化剂具有良好的电化学性能。

Supported Pt/C catalysts used in proton exchange membrane fuel cells （PEMFC） were prepared by the inorganic colloid method. The influences of pH value, concentration and temperature of solutions on the formation and stability of the PtO2 colloid were studied. The performances of Pt/C catalysts prepared with different concen- trations of HCHO reducing agents were analyzed. Transmission electron microscopy （TEM） results showed that the Pt/C catalyst with 3 nm platinum crystallites, a higher dispersion and a very narrow size distribution was achieved at optimal conditions. X-ray diffraction （XRD） analysis showed that the relative content of the Pt（lll） crystal face in the prepared Pt/C catalyst was increased, and this benefits the acceleration of the oxygen reduction reaction in PEMFC. The measurement results of I-E characteristics of a single PEMFC indicated that the Pt/ C catalyst prepared in this work exhibited better electrochemical performance.