reconstruction enhanced dual-site catalysis towards nitrate electroreduction to ammonia

Electro-reduction of nitrate to ammonia ( e -NRA) has been considered as a facile and promising approach to eliminate nitrate pollution and produce ammonia (NH 3 ) under ambient conditions. Nevertheless, in recent state-of-the-art studies, high faradaic efficiency towards NH 3 (FE NH 3 ) was usually achieved with a very negative working potential ( vs. RHE) or high overpotential, which causes not only low cost-efficiency but also structural degradation in electrocatalysts. In this work, we utilize the strategy of in situ electrochemical reconstruction to develop a highly efficient and durable electrocatalyst Ru&Cu/Cu 2 O (denoted as i -Cu 5 Ru 1 O x ) towards alkaline e -NRA. As a result, highly selective production of NH 3 can be achieved with an optimal FE NH 3 of around 95% even at a positive working potential of 0.1 V ( vs. RHE) or a small overpotential of 0.59 V. The catalyst shows no obvious degradation after consecutive e -NRA for 10 h. In addition, density functional theory (DFT) computations reveal that the excellent catalytic performance of Ru&Cu/Cu 2 O could be attributed to the synergy of the Cu/Ru dual-site, which results in significantly enhanced adsorption of NO 3 − ion and a more favorable proton supply for the hydrogenation during e -NRA. This work thus highlights the importance of dual-site synergy towards the electrochemical process with multiple elementary steps. We utilize an in situ strategy to develop a highly efficient and durable electrocatalyst Ru&Cu/Cu 2 O towards nitrate reduction to ammonia (e-NRA) in alkaline media. The good e-NRA performance is attributed to the synergy of Cu/Ru dual sites.