Electrifying nitrate conversion: Dual-metal-site catalysts as a game-changer for sustainable NH₃ production

Electrochemical nitrate reduction reaction (NO₃RR) emerges as a sustainable approach for converting residual nitrate pollutants into valuable ammonia under ambient conditions, offering a promising alternative to the energy-intensive Haber–Bosch process. Compared to single-metal-site electrocatalysts, dual-metal-site (DMS) electrocatalysts show synergistic effects between adjacent metal sites, effectively regulating the electronic state and enhancing the catalytic activity and selectivity for NO₃RR with multi-step proton and electron transfers. Further understanding on NO₃RR is of practical significance for design of efficient DMS electrocatalysts. This review aims to systematically investigate the recent advancement of DMS electrocatalysts for NO₃RR to ammonia synthesis, providing new understandings and insights into this catalytic process. The NO₃RR mechanism, artificial intelligence (AI)-driven DMS synthesis, DMS synthesis/characterization, and design of chemical reaction systems are categorized and discussed. DMS electrocatalysts for NO₃RR at the cathode can reduce the energy input for water oxidation, biomass oxidation reactions, and zinc-nitrate batteries, while simultaneously enhancing the yields of anode and cathode products. Finally, the remaining challenges and future perspectives for DMS electrocatalysts in NO₃RR are further discussed. This review provides in-depth guidance for rational design of dual-site electrocatalysts, facilitating practical and sustainable electrochemical processes in the near future.