High-throughput screening to predict highly active dual-atom catalysts for electrocatalytic reduction of nitrate to ammonia

Ammonia is an essential chemical owing to its importance in fertilizer production and other industrial applications. Electrocatalytic nitrate reduction to ammonia (NO₃RR) holds great promise for low-temperature ammonia production while simultaneously addressing nitrate-based environmental concerns. To provide the mechanistic understanding needed to design an effective electrocatalyst, we systematically investigated the catalytic performance of metal-based dual-atom catalysts (DACs) anchored on two-dimensional (2D) expanded phthalocyanine (Pc) for NO₃RR. We found that NO₃RR can efficiently produce ammonia on Cr₂-Pc, V₂-Pc, Ti₂-Pc, and Mn₂-Pc surfaces with low limiting potentials of − 0.02, − 0.25, − 0.34, and − 0.41 V_RHE, respectively. Moreover, using the free energy difference of *NO₃^- and *H as a descriptor, we found that the hydrogen evolution reaction is significantly suppressed on the DAC surface due to an ensemble effect in which the two metal atoms cooperate to selectively form ammonia. We performed high-throughput screening to develop an efficient metal-based DAC for NO₃^- reduction, followed by a mechanistic study to elucidate the NO₃RR pathway on the DAC. This work provides design information for advancing sustainable ammonia synthesis under ambient conditions.