铂铑合金电极上氧吸附特性的研究

Study on adsorption property of oxygen on Pt Rh alloy

采用快速动电位扫描方法对ＰｔＲｈ合金电极上氧的吸附过程进行了研究。结果表明，ＰｔＲｈ合金电极上氢的吸附是在接近平衡状态下进行的，而氧的吸附过程却是一个不可逆过程。随着合金电极当中Ｒｈ的含量的减少，氧的吸附峰的位置很明显地朝阳极方向移动。对ｗ（Ｒｈ）＜５０％的合金电极，其氧的吸附峰已经基本上与Ｐｔ电极的相重合。同时，在同一电极电位下，化学吸附氧的数量却随着合金当中Ｒｈ的含量的增加而明显增多。此外，还对合金电极表面预处理方法不同对其动电位ｉ，φ电线形状以及氧的解吸峰位置的影响进行了探讨。

The fast scan potentiodynamic polarization test was performed by studying the adsorption process of oxygen on Pt Rh Alloy. The results showed that the hydrogen adsorption on Pt Rh alloy was in equilibrium condition, but the oxygen adsorption was an irreversible process. With decreasing the Rh contents in the alloy electrode, the adsorption peak potential of oxygen obviously moved towards anodic direction. For the alloy of w (Rh)<50%, the adsorption peak of oxygen on Pt Rh electrode basically overlaped on that of Pt electrode. Meanwhile, at the same potential, the amount of chemisorption oxygen obviously increased with the increase of the Rh contents in the alloy. Besides, the effect of the surface pretreatment of the alloy electrode on the shape of i φ curve and the position of desorption peak of oxygen were discussed.