固液界面的力?电?化学耦合及在电催化体系中的应用

目前许多新型高效金属催化剂在设计制备中都考虑到表面力学因素, 例如层状结构、核壳结构等, 其表面高活性原子受到不同程度的应变作用. 应变可直接改变金属的能带带隙, 对催化剂表面的电化学反应产生显著影响, 是一种有效提升材料催化活性的新思路和制备高性能催化剂的新途径, 因此受到了科研工作者的广泛关注. 传统的材料应变工程手段存在着活性物质层的应变值难以精确定量, 并缺少实时调控以及制备工艺繁琐等难题, 导致应变与电催化活性相关性规律识别方面的理论和实验研究进展缓慢. 相比于传统的材料手段, 交变载荷产生的应变具有幅值和频率的可变性以及连续的调控性, 在实验中可以完全排除噪声、缺陷、空位、基底效应等其他外部或材料本征的影响因素. 该综述从经典固液界面热力学表述出发, 简要介绍了电催化体系中的力?电?化学耦合效应, 归纳总结目前电催化体系中应变施加的实验手段和分析方法, 并基于目前相关研究着重讨论在交变载荷作用下应变对金属表面电催化反应的作用机理, 最后从力学角度展望了表面力学在电催化体系中的研究重点及发展趋势. 

The electro-chemo-mechanical coupling at the solid-liquid interfaces and its applications to electrocatalysis

Many advanced catalysts have considered the positive effect of surface mechanics during their design and preparation, in which the high active atoms on the surface are under different strain states. Strain can directly change the bandgap of a metal, which has a significant impact on the electrochemical reaction that occurred at the electrocatalyst surface. It is a new idea and effective strategy to improve the electrocatalytic activity of materials. Traditional strain engineering based on material strategies is difficult to accurately quantify the strain value of an active layer, which results in the unclear recognition of the relation between strain and electrocatalytic activity. The strain induced by the alternating load has the advantages of tunable amplitude and frequency as well as continuous modulation. From the classical thermodynamic of solid-liquid interface, this review briefly introduces the electro-chemo-mechanical coupling in electrocatalytic systems, and summarizes the experimental methods and the analysis methods in use for studying the effect of strain on electrocatalytic reactivity. It is also discussed in detail on the mechanism of strain on the electrocatalytic reaction at the metal surface under alternating load. Finally, the development and application of surface mechanics in electrochemical systems are prospected from the perspective of mechanics.