磷钨酸对甲酸在碳载Pt催化剂上电氧化的促进作用

摘要

用X射线能谱(EDS)、X射线衍射(XRD)和电化学等测试技术研究了电解液中的磷钨酸(PWA)对甲酸在碳载Pt(Pt/C)催化剂电极上氧化的促进作用. 结果表明,PWA不但能提高甲酸在Pt/C催化剂电极上氧化的电催化活性,而且也能提高其电催化稳定性. 这种促进作用与电解液中PWA的浓度有关,当电解液中PWA的质量浓度为0.10 g/L时,这种促进作用最佳. 这主要是由于电解液中PWA质量浓度＞0.10 g/L时,吸附到电极表面的PWA的量太多,占据了Pt/C催化剂电极中Pt表面的部分活性位点,从而降低了催化剂的电催化性能.%The promoting action of phosphotungstic acid(PWA) in the electrolyte on the oxidation of formic acid at the carbon supported Pt(Pt/C) catalyst was investigated via EDS, XRD and electrochemical methods. It was found that PWA can increase not only the electrocatalytic activity of the Pt/C catalyst electrode for the oxidation of formic acid, but also the electrocatalytic stability. The promoting action is related to the PWA concentration. When the PWA concentration is 0.10 g/L, the promoting action is the best. This is mainly because when the PWA concentration is too high, overfull adsorbed PWA would partially cover the active points of the Pt/C catalyst, leading to the decrease in the electrocatalytic performance of the Pt/C catalyst.