次亚磷酸根在Pt电极上的电氧化研究

Electrochemical Oxidation of Hypophosphite Anions on Platinum Electrodes

用循环伏安法研究 H2 PO2 -在铂电极上的电氧化行为 ,并讨论电氧化的机理 .结果表明 ,在 0 .5mol/L H2 SO4 介质中 ,H2 PO2 -抑制氢和氧在 Pt电极上的吸附 ,并通过两种路径在 0 .4～ 1.2 V(vs.SCE)的电位范围发生氧化 :H2 PO2 -直接氧化形成 H2 PO3 -和 H2 PO2 -通过前置化学步骤形成吸附中间物 H3 PO3 ,然后进一步电氧化形成 H3 PO4 .所述机理可以较好地解释电位扫描速度。

The electrochemical oxidation of hypophosphite anions on platinum electrodes has been investigated by cyclic voltammetry and the electrooxidation mechanism has also been discussed. In 0.5 mol/L H 2SO 4 medium, H 2PO 2 - anions inhibit greatly electroadsorption of H atom and O atom on platinum electrode surface, and are electrooxidized by two ways in the potential range 0.4～1.2V(vs.SCE). The H 2PO 2 - anions are not only directly electrooxidized to H 2PO 3 -, but also indirectly oxidized to H 3PO 4 through the formation of intermediate product H 3PO 3ads. The proposed electrooxidation mechanism well explains the effects on voltammetric behaviour of the factors such as potential sweep rate, temperature of medium and hypophosphite concentration.