电催化限域效应研究

项目名称： 电催化限域效应研究

项目编号： No.21203142

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理化学

项目作者： 肖丽

作者单位： 武汉大学

项目金额： 25万元

中文摘要： 限域效应是指由于反应区域具有相对封闭的结构导致局部电子云异常分布和分子运动受限，从而对某些催化反应产生促进作用的现象。在电催化研究中，虽然有些现象看起来与限域效应有关，但目前尚无论述和运用电催化限域效应的文献报道。本项目拟以"磁控溅射?去合金化?退火"的方法构建具有纳米腔孔的模型电极，通过可控地调节电极中的空隙体积分数这一结构因子，对电催化限域效应进行准确指认、系统考察和定量评估。基于我们前期研究对限域效应有助于C-C键断裂的判断，本项目除考察典型的燃料电池反应，将重点研究乙醇等C2分子的电氧化反应；还将探索通过限域效应提升非铂催化剂性能的途径。对于具有明显限域效应的电催化体系，将通过差分电化学质谱与原位红外光谱方法研究其分子机理；通过密度泛函理论计算探讨其物理本质。本研究具有基础的科学意义，也有实际的应用价值，有望获得提升燃料电池催化剂性能的新途径，指导电化学器件的电极结构设计。

中文关键词： 限域效应；电催化；醇氧化；差分电化学质谱；全反射红外光谱

英文摘要： Confinement effects are a class of catalytic promotion phenomena caused by the relatively closed structure of the reaction region featuring in special distribution of local electron clouds and motion limitation of molecules. In electrocatalysis, although some phenomena seem to be related to the confinement effect, no discussion and application of confinement effects have been reported in the literature. We propose in this project a systematic study of the confinement effect in electrocatalysis through using model porous electrodes which are constructed by a "sputtering-dealloying-annealing" procedure. By controlling the volume fraction of voids in the electrode, we will be able to accurately identify and quantitatively evaluate the confinement effect. In addition to take a survey on typical fuel cell reactions, we will continue our previous effort of studying the confinement effect on C-C bond breaking, especially the electrooxidation of ethanol and other C2 molecules. We will also look at the possible promotion on the catalytic activity of non-platinum catalysts by confinement effects. For those electrocatalytic systems exhibiting clear confinement effects, we will use differential electrochemical mass spectrometry and in-situ infrared spectroscopy to study the relevant molecular mechanism and incorporate densi

英文关键词： confinement effects；electro-catalysis；alcohol oxidation；DEMS；FTIR