2D conductive metal–organic frameworks for NO electrochemical reduction: a first-principles study†

Designing flexible single-atom catalysts with tunable single-atom centers and coordination environments is crucial for highly active and selective electrochemical catalysis. Using density functional theory calculations, a range of 32 two-dimensional conductive metal–organic frameworks (cMOFs: TMX₄–HTPs, TM = Sc–Ni, X = N, O, P, S) were investigated as efficient catalysts for electrocatalytic nitric oxide reduction reaction (eNORR) towards ammonia. By screening for stability, selectivity, and activity, eight TMX₄–HTPs are identified as potential high-performance catalysts. Among them, MnO₄–HTP delivers the lowest overpotential of only 0.21 V. Using this system as an example, the solvent effect, protonation ability of the potential-limiting step, and constant potential model were additionally considered and simulated. The computed results further verify the predicted potential of these catalysts as eNORR catalysts. Furthermore, descriptors are obtained to evaluate the competitive ability of key adsorbates using the sure independence screening and sparsifying operator method. All parameters are related to the intrinsic properties of TM (such as electronegativity, valence electron number, first ionization energy, and relative atomic mass) without extensive calculations. This work paves the way for highly active and selective cMOF-based electrocatalysts for eNORR.