Pt电极上吸附原子对正丙醇电催化氧化性能的影响

用电化学循环伏安和石英晶体微天平研究了碱性介质中正丙醇在Pt电极和以Sb,S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上电催化氧化过程。结果表明正丙醇的氧化与溶液酸碱性关系密切。酸性介质中正丙醇在Pt电极上的CV曲线有两个正向氧化峰，而碱性介质中只有一个正向氧化峰，第二个氧化峰的消失可能是由于碱性介质中电极钝化引起的。与Pt电极相比较，饱和Sb吸附原子修饰的Pt电极使碱性介质中正丙醇氧化的峰电位负移了0.10V，峰电流增加了2．2倍，表现出显著的电催化活性。相反，Pt电极表面S吸附原子抑制了正丙醇的电氧化。还从表面质量变化提供了吸附原子电催化作用的新数据。

The Study on the Electrocatalytic Properties of n-propyl Alcohol in Alkaline Media on Pt Electrodes Modified with Adatoms

The processes of adsorption and oxidation of n-propyl a lcohol in alkaline media on Pt and Pt modified with Sb and S (Pt/Sb ad and Pt/S ad ) electrodes were studied by using cyclic voltammetry and el ectrochemical quartz crystal microbalance (EQCM). The results demonstrated that the oxidation of n-propyl alcohol depends strongly on oxidation states of elec trode surface and the acidity of the solution. Sb adatoms on Pt surface can ads orb oxygen at relatively low potentials, and exhibit catalytic effects for n-pr opyl alcohol oxidation. In comparison with the case of Pt electrode, the oxidat ion peak potential of n-propyl alcohol on Pt surface modified with Sb was negat ively shifted about 100 mV with peak current being doubly increased. In a contr ary, the oxidation of S adatoms consumes oxygen species of Pt electrode surface . As a consequence, the oxidation of n-propyl alcohol was inhibited by the pre sence of S ad. The EQCM studies provided quantitative results of surfac e mass changes during n-propyl alcohol oxidation, and have thrown new light in elucidating different effects of adatoms Sb ad and S ad on Pt e lectrode towards n-propyl alcohol oxidation.