Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki 444-8585, Japan.
J Chem Phys. 2013 Sep 14;139(10):104101. doi: 10.1063/1.4820360.
We present a theoretical method to investigate electrochemical processes on the basis of a finite-temperature density functional theory (FT-DFT) approach combined with our recently developed open-boundary cluster model (OCM). A semi-infinite electrode is well mimicked by a finite-sized simple cluster with an open quantum boundary condition rationalized by OCM. An equilibrium state between adsorbates and an electrode is described by the grand canonical formulation of FT-DFT. These implements allow us to calculate electronic properties of an adsorbate and electrode system at a constant chemical potential μ, i.e., electrode potential. A solvation effect is approximated by a conductor-like polarized continuum model. The method is applied to the electrochemical processes of Ag(+) adsorption on Au(111) and Ag(111). The present constant μ approach has proved essential to electrochemical systems, demonstrating that the method qualitatively reproduces the experimental evidence that Ag(+) adsorbs more on the Au electrode than the Ag one, while the conventional quantum chemistry approach with a constant number of electrons incorrectly gives exactly the opposite result.
我们提出了一种基于有限温度密度泛函理论（FT-DFT）方法结合我们最近开发的开放边界团簇模型（OCM）的电化学过程的理论方法。通过 OCM 合理化的开放量子边界条件，半无限电极可以很好地模拟为有限尺寸的简单团簇。FT-DFT 的巨正则形式描述了吸附物和电极之间的平衡状态。这些实现使我们能够在恒定化学势μ（即电极电位）下计算吸附物和电极系统的电子性质。溶剂化效应通过导体类似的极化连续体模型进行近似。该方法应用于 Ag(+)在 Au(111)和 Ag(111)上的电化学过程。本研究的μ常数方法已被证明对电化学系统至关重要，证明了该方法定性地再现了实验证据，即 Ag(+)在 Au 电极上的吸附比 Ag 电极上的吸附更多，而具有恒定电子数的传统量子化学方法则给出了完全相反的结果。
