甲醇在Pt-Sn/Pb电极上的氧化行为 Ⅱ.氧化反应动力学特征的研究  

THE ELECTROCATALYTIC OXIDATION OF METHANOL ON Pt-Sn/Pb ELECTRODE Ⅱ.INVESTIGATIONS OF KINETICS AND MECHANISM OF THE OXIDATION

作　　者：袁钧卢[1] 程实[1] 颜涌捷[1] 陈丕亚 

机构地区：[1]华东化工学院

出　　处：《燃料化学学报》1991年第4期380-384,共5页Journal of Fuel Chemistry and Technology

摘　　要：在甲醇燃料电池体系中,已确信甲醇会在铂电极上形成强吸附的中间物种:(1)这一吸附中间物种可与从水中得到的氧发生反应:(2)(3)为研究反应机理,采用过各种实验手段分析B_(ad(?))。本工作采用旋转园盘电极的电化学实验方法研究了甲醇氧化反应过程的中间物种,并求取反应过程的动力学参数以探讨氧化反应的机理,进而分析了双金属催化剂的作用机理。By using the rotating disk electrode (RDE) technique, the ratio of the amount of electric charge required in the adsorption to that in the oxidation of methanol, number of electrons transferred and the reaction rate constants for methanol electrocatalytic oxidation were measured. It has been determined that adsorption involves four electrons and oxidation two electrons.It is inferred that(CO)_(ads) is the most likely adsorbed intermediate species,in other words the reaction would follow thepath:CH_3OH→(CO)_(ads)+4H^++4e(CO)_(ads)+H_2O→CO_2+2H^++2e The improvement of catalytic activity and stability of the electrode for methanol oxidation is achieved by the proper addition of tin atoms which modifies not only the adsorption characters of Pt but the geometrical factors of the electrods surface as well. Two active Pt sites takc part in the formation of(CO)_(ads), on the Pt-Sn/Pb electrode,If tin atoms occupy one third of the electrode surface,only two active Pt sites would be adjacent to each other which is favorable for the formation of(CO)_(ads).The adsorption of(CO)_(ads) is much weaker than that of(COH)_(ads) on Pt,so it is readily further oxidized and the electroed catalytic activity could be maintained longer.

关 键 词：甲醇 电极 氧化 反应动力学 铂 锡 

分 类 号：O623.411[理学—有机化学]