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.