电化学活化条件对Pt/C催化剂甲醇电氧化催化活性的影响

利用亚硫酸路线和亚锡酸法合成了两种Pt/C催化剂,并利用循环伏安技术,详细地研究了循环伏安高电位和活化方式对Pt/C催化剂的甲醇电氧化催化活性的影响.研究结果表明:在改变高电位的逐步循环伏安活化方式下,不同的Pt/C催化剂的活化存在有不同的最优循环伏安高电位;在最优高电位下,一次性活化方式对亚锡酸法Pt/C催化剂的活化最为有效.不同的活化条件产生不同的催化活性,主要原因在于不同的活化过程形成的最终的Pt的存在形式不一样,致使催化剂对水和阴离子具有不同的吸附能力和吸附速率.

Effect of electrochemical activation condition on the catalytic activity of Pt/C catalysts for methanol electro-oxidation

By means of the cyclic voltammograrn, the effects of upper potential and activation mode on the catalytic activity of two Pt/C catalysts prepared by the sulfurous route and the stannous method for methanol electro- oxidation were investigated. It is showed that different catalysts obtains different optimistical upper potentials in step-by step activation by changing upper potential. At the optimum upper potential, one-step activation is more effective than step-by step activation for the stannous Pt/C catalyst. Different activities obtained under different activation modes indicates that Pt is transformed into different states during different activation processes which endow the resultant catalyst with the distinct adsorption capability and rate for anions and water.