Cu^2＋对质子交换膜燃料电池氧电极性能的影响

Effect of Impurity Cu^(2+) on Oxygen Electrode in PEMFC

以旋转圆盘电极模拟PEMFC阴极,计时库仑、循环伏安、线性扫描等电化学方法研究Cu2+电解液对碳载铂催化剂电化学活性和氧还原性能的影响.结果表明,在恒电位0.49 V下,Pt/C催化剂活性比表面(ECA)明显减小,此际基底可能发生Cu欠电位沉积,从而掩盖催化剂的活性比表面;数据拟合指明Cu欠电位沉积占据催化剂表面部分氧原子吸附点位,使该点位桥式吸附的氧原子转变为顶式吸附氧原子.

Rotating disk electrode was adopted in this paper to simulate the cathode in PEMFC. In the Cu^2＋ electrolyte, the influence of impurity Cu^2＋ on Carbon-Supported Pt Catalysts was investigated by using electrochemical measurements such as ehronocoulometry, cyclic voltammetry and linear sweep. Experimental results showed that, after constant voltage at 0.49 V, the ECA of Pt/C decreased dramatically, it＇ s perhaps under potential deposition of Cu might occur on the substrate. Meanwhile the change of ORR Tafel scope reaction is very large. It might be because oxygen adsorption sites are occupied by Cu atoms after they under potential deposit on surface of Pt/C catalyst, and the adsorption of oxygen on eatalyst surfaee change from bridge type to top type.