Screening and Discovery of Metal Compound Active Sites for Strong and Selective Adsorption of N2 in Air

Photocatalytic nitrogen fixation has the potential to provide a greener route for producing nitrogen‐based fertilizers under ambient conditions. Computational screening is a promising route to discover new materials for the nitrogen fixation process, but requires identifying “descriptors” that can be efficiently computed. In this work, we argue that selectivity toward the adsorption of molecular nitrogen and oxygen can act as a key descriptor. A catalyst that can selectively adsorb nitrogen and resist poisoning of oxygen and other molecules present in air has the potential to facilitate the nitrogen fixation process under ambient conditions. We provide a framework for active site screening based on multifidelity density functional theory (DFT) calculations for a range of metal oxides, oxyborides, and oxyphosphides. The screening methodology consists of initial low‐fidelity fixed geometry calculations and a second screening in which more expensive geometry optimizations were performed. The approach identifies promising active sites on several TiO2 polymorph surfaces and a VBO4 surface, and the full nitrogen reduction pathway is studied with the BEEF‐vdW and HSE06 functionals on two active sites. The findings suggest that metastable TiO2 polymorphs may play a role in photocatalytic nitrogen fixation, and that VBO4 may be an interesting material for further studies. In the search for greener nitrogen‐based fertilizer production, we propose a computational screening method to identify promising catalysts. We propose strong and selective adsorption of molecular nitrogen as a descriptor and present a multifidelity DFT‐based screening framework for a range of transition‐metal compounds. Our findings reveal that metastable TiO2 and VBO4 surfaces exhibit interesting reactivity for reduction of nitrogen in air.