质子交换膜燃料电池Pd修饰Pt/C催化剂的电催化性能

通过对Pt催化剂表面进行Pd修饰提高质子交换膜燃料电池阴极催化剂的氧还原反应(ORR)活性. 采用乙二醇还原法制备了不同比例的Pd修饰Pt/C催化剂. 透射电镜(TEM)和X射线衍射(XRD)测试结果表明, 制备的催化剂贵金属颗粒粒径主要分布在1.75～2.50 nm之间, 并均匀地分散在碳载体表面. 循环伏安方法(CV)研究表明Pd修饰Pt/C催化剂的电化学活性面积低于传统的Pt/C催化剂. 但通过旋转圆盘电极(RDE)测试研究发现, 制备的催化剂具有比传统Pt/C催化剂高的ORR活性.

Electrocatalytic Properties of Pd Modified Pt/C Catalysts for Proton Exchange Membrane Fuel Cell

Differently with alloy catalysts, Pd has been used to promote the oxygen reduction reaction (ORR) activity of the cathode catalyst in fuel cells by decorating the surface of Pt supported on carbon black with Pd. Both the Pt-Pd/C catalyst with different ratios of Pt to Pd and the Pt/C catalyst of reference were fabricated by polyol processes in ethylene glycol solution. The results of XRD and TEM show that the average size of Pt-Pd noble metal particles is 1.75～2.50 nm which are highly dispersed on the carbon supports. The hydrogen desorption property and electrocatalytic activity of the Pt-Pd/C catalyst with different ratios of Pt to Pd and the Pt/C catalyst were investigated by cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements. The CV test shows that the Pd-modified Pt/C catalysts have lower electrochemical surface area (ECSA) than Pt/C catalyst. However, compared with the conventional Pt/C catalyst, the Pd-modified Pt/C catalyst presents a high ORR activity in RDE measurements, although both of them have a similar behavior of kinetics of oxygen reduction based on their Tafel slope characteristics.