CAJ | 학술논문

采用NaBH4还原法制备了XC-72碳黑负载的Pt电催化剂,并在化学还原后用H2O2处理部分催化剂以改变Pt的氧化状态,以期改善Pt活性中心上水的离解而提高催化活性.X射线光电子能谱结果表明,经H2O2处理的催化剂含有较多的氧化态Pt.通过循环伏安法和记时电流法考察了经处理和未经处理的催化剂在酸性条件下的甲醇氧化的催化活性.结果表明,经氧化法产生的含有较多氧化态Pt的催化剂并不能提供活性状态的氧以去除阻碍反应的CO中间体,含有较多金属状态Pt的催化剂活性反而更高,抗CO性能更佳.
채용NaBH4환원법제비료XC-72탄흑부재적Pt전최화제,병재화학환원후용H2O2처리부분최화제이개변Pt적양화상태,이기개선Pt활성중심상수적리해이제고최화활성.X사선광전자능보결과표명,경H2O2처리적최화제함유교다적양화태Pt.통과순배복안법화기시전류법고찰료경처리화미경처리적최화제재산성조건하적갑순양화적최화활성.결과표명,경양화법산생적함유교다양화태Pt적최화제병불능제공활성상태적양이거제조애반응적CO중간체,함유교다금속상태Pt적최화제활성반이경고,항CO성능경가.
Pt catalysts supported on Vulcan XC-72 carbon were prepared by the NaBH4 reduction of H2PtCl6 in the presence of a carbon support.One of the catalysts was deliberately treated with H2O2 after chemical reduction to alter the oxidation state of Pt and to promote methanol oxidation through more efficient water dissociation on the Pt sites.X-ray photoelectron spectroscopy confirmed that H2O2 treatment resulted in a more oxidized Pt catalyst.The electrooxidation of methanol over treated and untreated Pt catalysts in acidic solutions at room temperature was investigated by cyclic voltammetry and chronoamperometry.Despite their design,the more oxidized Pt catalysts could not supply active oxygen capable of removing the reaction-inhibiting CO-like reaction intermediates.As a result the catalytic activity was still largely dependent on the Pt oxidation state with the more "metallic" catalyst showing higher methanol oxidation activity and more CO tolerance.