Descriptor of Nonlocal Effects in Oxidative Adsorption on Metal Oxides

Abstract

The catalytic properties of transition-metal oxides (TMOs) are largely defined by their surface bonding. However, an accurate description of adsorption in these systems remains elusive. In this study, we focus on descriptors of catalytic activity, oxygen evolution, and reduction reactions using the Integrated Crystal Orbital Hamilton Population (ICOHP), which has recently been shown to be a good descriptor [ACS Catal. 2024, 14 (7), 5286-5296]. We use bond-decomposed analysis and expansion beyond the active site to propose an improved ICOHP descriptor, which now includes nonlocal effects of adsorption. This approach is very effective for all systems, including previously excluded d0-cases. The extrapolated size change in ICOHP leads to a strong linear correlation, close to unity for 4d and 5d, and half that for 3d. We attribute this difference to adsorption-induced changes in magnetic moments. We argue that the nonbonding characteristic of 3d high-spin metals cannot be captured by ICOHP alone. Overall, the size-extrapolated approach to the ICOHP descriptor not only improves prediction accuracy but also enhances physical interpretation and underscores the importance of considering both local and more extended bonding environments in the catalytic design of pure oxides and mixed oxides.