ELECTROCATALYTIC ACTIVITY OF METALS IN ELECTRO-CHEMICAL REACTION

COイD22エD2 is electrochemically reduced to various products， depending on the electrode metals。Pt can reduce CO-D22-D2 to CO strongly adsorbed on the electrode by hydrogen atoms preadsorbed on the electrode。我们研究了使用高指数platinum单晶体电的反应。The activity of the electrodes for the electrochemical reduction of CO的D22 depends highly on atomic configuration of the electrode。活动顺序为（111） < （997） < （332） < （221） < （110） < （331） < （110）。此订单同意使用电极表面的步进原子密度。We presumed that the hydrogen atoms active for the reaction are the adsorbed hydrogen atoms at the 4-fold sites of the stepped atoms。The electrochemical reduction of CO-D22-D2 was also conducted with platinum electrodes in the electrolyte solution of acetonitrile-water mix #。主要产品是不含水的乙腈中的氧酸，而含水的电解质中的正式酸。他们一直在不断地从表面上观察到铂的电极，在表面上的存在中被强烈吸收的CO。铅和汞的产品选择性产生了影响。Machanism was ratinalized in terms of prevention of the adsorption of the CO D22 anion radical on the electrode surface owing to the strongly adsorbed CO。High index plane single crystals of copper were also studied for the electrochemical reduction of CO D22。产品的选择性被电的晶体方向的晶体作用明显地影响了。（111）表面对甲基形成是有利的，（100）年多的乙烯。我们使用了一些电极，主要由（100）和（111）步骤组成。（711）方向，由（100）表面和（111）步骤提供高乙烯选择性的4个原子行组成。乙烯形成可能由（111）原子配置中的（100）步骤激活。

COィイD22ィエD2 is electrochemically reduced to various products, depending on the electrode metals. Pt can reduce COィイD22ィエD2 to CO strongly adsorbed on the electrode by hydrogen atoms preadsorbed on the electrode. We studied this reaction using high index platinum single crystal electrodes. The activity of the electrodes for the electrochemical reduction of COィイD22ィエD2 depends highly on atomic configuration of the electrode. The activity order is (111) < (997) < (332) < (221) < (110) < (331) < (110). This order agrees with the step atom density of the electrode surface. We presumed that the hydrogen atoms active for the reaction are the adsorbed hydrogen atoms at the 4-fold sites of the stepped atoms.The electrochemical reduction of COィイD22ィエD2 was also conducted with platinum electrodes in the electrolyte solution of acetonitrile-water mixtures. The main products are oxalic acid in water free acetonitrile, and formic acid in the electrolyte which contains some concentrations of water. They were obtained continuously from the platinum electrode in spite of the presence of strongly adsorbed CO on the surface. The product selectivity resembles that of Pb and Hg. The machanism was ratinalized in terms of prevention of the adsorption of the COィイD22ィエD2 anion radical on the electrode surface owing to the strongly adsorbed CO.High index plane single crystals of copper were also studied for the electrochemical reduction of COィイD22ィエD2. The product selectivity is remarkably affected by the crystal orientation of the electrode. (111) surface is favorable for methane formation, and (100) yields more ethylene. We employed some electrodes composed mainly of (100) and small fraction of (111) steps. (711) orientation, composed of 4 atomic rows of (100) surface and (111) step gave high ethylene selectivity. The ethylene formation may be activated by the presence of (111) step in (100) atomic configuration.