High‐Throughput Screening of Heterogeneous Transition Metal Dual‐Atom Catalysts by Synergistic Effect for Nitrate Reduction to Ammonia

Abstract

AbstractNitrate reduction to ammonia has attracted much attention for nitrate (NO3‐) removal and ammonia (NH3) production. Identifying promising catalyst for active nitrate electroreduction reaction (NO3RR) is critical to realize efficient upscaling synthesis of NH3 under low‐temperature condition. For this purpose, by means of spin‐polarized first‐principles calculations, the NO3RR performance on a series of graphitic carbon nitride (g‐CN) supported double‐atom catalysts (denoted as M1M2@g‐CN) are systematically investigated. The synergistic effect of heterogeneous dual‐metal sites can bring out tunable activity and selectivity for NO3RR. Amongst 21 candidates examined, FeMo@g‐CN and CrMo@g‐CN possess a high performance with low limiting potentials of ‐0.34 and ‐0.39 V, respectively. The activities can be attributed to a synergistic effect of the M1M2 dimer d orbitals coupling with the anti‐bonding orbital of NO3‐. The dissociation of deposited FeMo and CrMo dimers into two separated monomers is proved to be difficult, ensuring the kinetic stability of M1M2@g‐CN. Furthermore, the dual‐metal decorated on g‐CN significantly reduces the bandgap of g‐CN and broadens the adsorption window of visible light, implying its great promise for photocatalysis. This work opens a new avenue for future theoretical and experimental design related to NO3RR photo‐/electrocatalysts.