Computational screening of two-dimensional conductive metal-organic frameworks as electrocatalysts for the nitric oxide reduction reaction

The electrocatalytic reduction of nitric oxide (NORR) is an effective and economical method to eliminate NO by converting it into valuable ammonia (NH3). However, exploring and screening suitable catalysts with both high activity and selectivity remain a great challenge. Herein, we systematically study the potential of two-dimensional conductive metal-organic frameworks (2D c-MOFs), namely, TM3(C6O6)2 monolayers (TM = transition metals from group 3 to 11) as single-atom catalysts toward NO-to-NH3 conversion. Among the 25 candidates, Mo3(C6O6)2 with high stability, activity, and selectivity was successfully screened out through a four-step screening strategy and high-throughput first principles calculations. In particular, the Gibbs free energy of NO (Delta G*NO) is applied as an effective descriptor for potential NORR catalysts. This work not only provides an effective strategy to screen out TM3(C6O6)2 for electrochemical NO-to-NH3 conversion, but also opens a new avenue for designing high-performance 2D c-MOFs towards the NORR. Through a "four-step" screening strategy, Mo3(C6O6)2 is selected from 25 2D c-MOFs as the NORR electrocatalyst, which has a low limiting potential of -0.20 V, as well as strong capability to suppress competing H2, N2, and N2O formation.