IN-SITU CHARACTERIZATION OF SURFACES ON NEW ELECTRODE FOR FUEL CELLS AND ELECTROLYSIS

X射线光电子能谱是无损测定样品表面价态和成分的有效方法。为了更好地理解在暴露于相对低的氧化能力的电极表面上促进反应的化学物质，表面的原位测定是特别必要的。XPS中的原位表征是在暴露于X射线光电子能谱仪的高真空之前确定表面没有暴露于空气中的表面物种的氧化。在本工作中，电解池中的电极用脱气的蒸馏水冲洗，在不暴露于空气的情况下转移到地球仪盒中，并安装在用于X-射线的气密转移容器上。在地球仪箱中氮气气氛下进行X射线光电子能谱仪。在不受空气氧化不利影响的情况下，已经获得了电极表面的有用信息，这些电极包括用于氢、甲烷、乙烷和丙烷作为燃料的燃料电池电极，用于电解海水中放出氢、氯和氧的电极，以及用于电化学氧化亚硫酸盐的电极。在燃料电池非晶态合金电极的研究中，添加铂族元素和锡可以有效地提高非晶态合金电极的电催化活性。证实了加速燃料氧化的Sn^<2+>/Sn^<4+>氧化还原体系的存在。当电极在电解后暴露于空气中时，甚至铂族元素也容易被氧化物覆盖，因此用于电极反应的有效物种的规格是困难的。事实上，铂族元素直接以金属状态作用于燃料和亚硫酸盐的氧化。这些不能得到到目前为止，通过异位表面表征。

X-ray photoelectron spectroscopy is an effective method for nondestructive determination of valence and composition in the specimen surface. In-situ determination of the surface is particularly necessary for a better understanding of chemical species contributing to the reaction on the electrode surface exposed to relatively low oxidizing power. In-situ characterization in XPS is to determine the surface without oxidation of the surface species as a result of exposure to air before being exposed to high vacuum of the X-ray photoelectron spectrometer.In the present work an electrode in an electrolytic cell is rinsed with deaerated distillled water, transferred without air exposure into a globe box and is mounted on an air-tight transfer vessel for X-ray photoelectron spectrometer under nitrogen atmosphere in the globe box. Useful information has been obtained for the electrode surface without the detrimental effect of air oxidation.These include fuel cell electrodes for hydrogen, methane, ethane and propane as fuels, electrodes for evolution of hydrogen, chlorine and oxygen in electrolysis of seawater and electrodes for electrochemical oxidation of sulfite. In the study of amorphous alloy electrodes for fuel cells additions of platinum group elements and tin are effective in enhancing the electrocatalytic activity. The presence of a redox system of Sn^<2+>/Sn^<4+> which accelerates oxidation of fuels is confirmed. When the electrode is exposed to air after electrolysis, even platinum group elements are readily covered with oxides and hence the specification of the effective species for the electrode reactions is difficult. In fact platinum group elements directly act in the metallic state for oxidation of fuels and sulfite. These could not be obtained so far by ex-situ surface characterization.