甲醇在Pt-Sn/Pb电极上的氧化行为——Ⅰ.电极催化特性的研究

THE ELECTROCATALYTIC OXIDATION OF METHANOL ON Pt-Sn/Pb ELECTRODE——I.STUDIES ON CATALYTIC PERFORMANCES OF THE ELECTRODE

采用欠电位沉积法,以铅电极作基体制备了负载型Pt-Sn双金属催化电极。应用循环伏安法和电位阶跃法研究了各种因素对该电极的催化活性和稳定性的影响,并应用XPS和AES技术分析了该电极的表面物性。该电极对酸性介质中的甲醇氧化反应显示出高于Pt-Sn/Pt电极的催化活性和稳定性。

Cyclic voltammetry and potential step method have been used to study the effects of different factors on the catalytic performances of Pt-Sn/Pb electrodes prepared by the underpotential deposition of Pt and Sn on lead XPS,AES investigation on these electrodes have been carried out to determine their surface properties.The Pt-Sn/Pb electrode shows enhanced catalytic activity for the oxidation of methanol in a solution of 1 mol/L methanol and 1 mol/L sulfuric acid attaining a current density of 190mA/cm^2.The optimized preparation conditions are as follows:concentration of stannous ion in the underpotential deposition solution 26.5-35.5%,codeposition time 10 minutes and codeposition potential around 0.15V.Maximun catalytic stability was obtained when the atomic ratio of Sn/Pt on lead surface was 1/2.