Adsorbate Entropies with Complete Potential Energy Sampling in Microkinetic Modeling

The
influence of different approximations on adsorbate entropies
is investigated for density functional theory based mean-field kinetic
modeling. Using CO oxidation over Pt(111) as a prototypical reaction,
we compare four approximations: the harmonic approximation, the hindered
translator, the free translator, and complete potential energy sampling
(CPES). The CPES method results in particularly good agreement with
previously measured experimental data. Given its general applicability
and moderate computational cost, the CPES method stands out as a preferable
option to describe adsorbate entropies.

本研究针对基于密度泛函理论（density functional theory）的平均场动力学建模，探究了不同近似方法对吸附质熵的影响。以Pt(111)晶面上的一氧化碳氧化反应作为典型模型反应，本研究对比了四类近似方法：简谐近似（harmonic approximation）、受阻平移近似（hindered translator）、自由平移近似（free translator）以及全势能采样（complete potential energy sampling，CPES）。全势能采样（CPES）方法的计算结果与此前实测的实验数据吻合度尤为优异。鉴于其普适性较强且计算成本适中，全势能采样（CPES）方法成为描述吸附质熵的更优选择。