(218d) First-Principles-Derived Structure-Energy Relationship for Surface Oxides

Metal-supported, 2-dimensional surface oxide monolayers represent an emerging class of catalysts for a variety of applications, ranging from biomass conversion to electrocatalysis. A tremendous challenge with modeling such materials is their atomic structure, which is typically unknown. Commonly employed structure prediction methods (simulated annealing, evolutionary algorithms) require accurate force fields, which are either expensive (density functional theory), or too complex and have transferability issues (ReaxFF).

Herein, we show that the systematic reduction of Kohn-Sham equations via the Harris energy functional leads to a simple structure-energy relationship involving only interatomic distances and coordination numbers for systems, in which angular dependence of energy is not important. The model reproduces the functional dependence of the metal cohesive energy on geometric characteristics, and its connection to molecular orbital theory allows generalizations to surface oxides. We assess the model performance for Co_xO_y/Pt(111) monolayer structures and investigate the transferability of its parameters.