Electrical-Driven Directed-Evolution of Copper Nanowires Catalysts for Efficient Nitrate Reduction to Ammonia.

The electrocatalytic conversion of nitrate (NO 3 - ) to NH 3 (NO 3 RR) at ambient conditions offers a promising alternative to the Haber-Bosch process. The pivotal factors in optimizing the proficient conversion of NO 3 - into NH 3 include enhancing the adsorption capabilities of the intermediates on the catalyst surface and expediting the hydrogenation steps. Herein, the Cu/Cu 2 O/Pi NWs catalyst is designed based on the directed-evolution strategy to achieve an efficient reduction of NO 3 ‾. Benefiting from the synergistic effect of the O V -enriched Cu 2 O phase developed during the directed-evolution process and the pristine Cu phase, the catalyst exhibits improved adsorption performance for diverse NO 3 RR intermediates. Additionally, the phosphate group anchored on the catalyst's surface during the directed-evolution process facilitates water electrolysis, thereby generating H ads on the catalyst surface and promoting the hydrogenation step of NO 3 RR. As a result, the Cu/Cu 2 O/Pi NWs catalyst shows an excellent FE for NH 3 (96.6%) and super-high NH 3 yield rate of 1.2 mol h -1  g cat. -1 in 1 m KOH and 0.1 m KNO 3 solution at -0.5 V versus RHE. Moreover, the catalyst's stability is enhanced by the stabilizing influence of the phosphate group on the Cu 2 O phase. This work highlights the promise of a directed-evolution approach in designing catalysts for NO 3 RR.