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

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