摘要
本文研究玻碳电极(GCE)表面Cr^(3+)/Cr^(2+)氧化还原反应产物和沉积的Au、Pb催化剂的价态以及它们对Cr^(3+)/Cr^(2+)反应的催化作用。XPS研究结果表明,Cr^(3+)/Cr^(2+)氧化还原反应产物无Cr^0或其它价态的化合物生成。Au、Pb作为催化剂以金属零价形式沉积在GCE表面。随Au、Pb光电子峰强度的变化,它们对Cr^(3+)/Cr^(2+)氧化还原反应呈现不同的催化作用。
The valence states of Cr3+/Cr2+ redox reaction products and Au and Pb catalysts deposited on glassy carbon electrode ( GCE ) and their catalytic characterestics for Cr3+/Cr2+ redox reaction were studied by XPS.
Only the peak of Cr3 + at 577 eV was found in Cr 2p XPS spectra. This indicated that the products of redox reaction are Cr3+ and Cr2+, and no Cro or products with other valence states is formed. As compared with pure Au 4 f XPS spectra, two peaks at the same positions of 83.8 eV and 87.7 eV can be seen, indicating that Au catalyst exhibits metallic state with zero valence as deposited on GCE. In the Pb 4 f XPS spectra of Pb catalysts and corresponding curve-fitting spectra, two peaks of Pb++ and Pb overlap, and Pb+ + peaks is stronger than Pb peaks.These results point out that Pb exists in the form of Pbo on GCE acting as a catalyst for Cr3+/Cr2+ redox reaction. With the change of the ratio of Au and Pb atom numbers, Au, Pb catalysts show different catalytic behavior for Cr3+/Cr2+ redox reaction. When the ratio is 0.73, they exhibit the best catalytic activity and reversibility.
出处
《分子催化》
EI
CAS
CSCD
1990年第2期122-127,共6页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金
