Bond-Energy-Integrated Descriptor for Oxygen Electrocatalysis of Transition Metal Oxides

Unraveling a descriptor of catalytic reactivity is essential for fast screening catalysts for a given reaction. Transition metal (TM) compounds have been widely used for oxygen electrocatalysis. Nevertheless, there is a lack of an exact descriptor to predict their catalytic behavior so far. Herein, we propose that the bond-energy-integrated orbitalwise coordination number ( CN ̅ sd ), which takes into account both geometrical and electronic structures around the active site, can serve as a simple and accurate descriptor for catalysts consisting of TM oxides (TMOs) as well as avoid excessive computation burden. This descriptor exhibits a strong scaling relation with the activity in oxygen electrocatalysis, with a goodness of fit higher than those of the usual coordination number (cn), the generalized coordination number ( CN ̅ ), and the orbitalwise coordination number (CN α ). Especially, the theoretical prediction made by the CN ̅ sd descriptor is very consistent with experimental results and universal for various TMOs (e.g., MnO x and RuO 2 ), enabling the rational design of novel catalysts.