Functional partitioning synergistically enhances multi-scenario nitrate reduction.

ABSTRACT

The promising electrocatalytic nitrate reduction reaction (eNitRR) for distributed ammonia synthesis requires the fine design of functionally compartmentalised and synergistically complementary integrated catalysts to meet the needs of low-cost and efficient ammonia synthesis. Herein, the partitionable CoP3 and Cu3P modules were built on the copper foam substrate, and the functional differentiation promoted the catalytic performance of the surface accordion-like CoP3/Cu3P@CF for eNitRR in complex water environment. Where the ammonia yield rate is as high as 23988.2 µg h-1 cm-2, and the Faradaic efficiency is close to 100 %. With CoP3/Cu3P@CF as the core, the assembled high-performance Zn-nitrate flow battery can realize the dual function of ammonia production and power supply, and can also realize the continuous production of ammonia with high selectivity driven by solar energy. The ammonia recovery reaches 753.9 mg L-1, which shows the superiority of CoP3/Cu3P@CF in multiple application scenarios and provides important experience for the vigorous development of eNitRR. Density functional theory calculation reveal that CoP3 and Cu3P sites play a relay synergistic role in eNitRR catalyzed by CoP3/Cu3P@CF. CoP3 first promotes the activation of NO3- to *NO3H, and then continuously provides proton hydrogen for the eNitRR on the surface of Cu3P, which relays the synergistic catalytic effect to promote the efficient conversion of NO3- to NH3. This study not only develops a catalyst that can promote the efficient reduction of NO3- to ammonia through an easy-to-obtain innovative strategy, but also provides an alternative strategy for the development of eNitRR that is suitable for multiple scenarios and meets the production conditions.