Promoting Ampere-Level Nitrate Reduction to Ammonia Through Strong Oxide-Oxide Interaction.

The electrochemical reduction of nitrate to value-added ammonia offers a promising approach for removing nitrate pollutants from wastewater, combining energy efficiency, and environmental sustainability. However, developing industrially viable catalysts that combine high efficiency, low-cost, and high durability remains a significant challenge. Herein, cobalt oxide (Co3O4) nanoparticles are anchored onto the copper oxide (CuO) nanosheets support (Co3O4@CuO) to boost the electroreduction of nitrate to ammonia via a strong oxide-oxide interaction. The optimized Co3O4@CuO catalyst exhibits a superb nitrate reduction performance, including a high ammonia Faradaic efficiency of 93.4 % at an ampere-level current density of approximately 2500 mA cm-2. Mechanistic investigations reveal that the strong oxide-oxide interaction between Co3O4 and CuO regulates the adsorption configuration of nitrite and the subsequent hydrogenation process. This interaction can effectively control the overall reaction pathway, thereby enhancing the yield and selectivity of ammonia. The strategic combination of these oxide materials provides a guiding framework for developing high-performance catalytic systems.