High-Throughput Screening of Efficient Biatom Catalysts Based on Monolayer Carbon Nitride for the Nitric Oxide Reduction Reaction

Exploring efficient catalysts for the nitric oxide reduction reaction (NORR) toward NH3 synthesis is becoming increasingly important for tackling both NH3 synthesis and NO removal problems. Currently, only a few NORR catalysts have been proposed, which are exclusively concentrated on bulk metals or single-atom catalysts. Here, taking monolayer C2N as an example, we explore the potential of biatom catalysts (BACs) for direct NO-to-NH3 conversion by means of high-throughput first-principles calculations. According to a rational five-step screening strategy, a promising BAC of Cr2-C2N is successfully screened out, exhibiting high stability, activity, and selectivity and a low kinetic barrier for the NORR toward NH3 synthesis. Importantly, the adsorption energy of N atoms (ΔE*N) and the Gibbs free energy of NO adsorption (ΔG*NO) are identified as effective descriptors for efficient NORR catalysts. In addition, through tuning the NO coverage, the NORR on Cr2-C2N could produce different products of NH3 and N2O, providing the possibility to realize controllable multiproduct BACs. These findings not only suggest the great potential of BACs for direct NO-to-NH3 conversion but also help in rationally designing high-performance BACs.