Synergy between Cu and Co in a Layered Double Hydroxide Enables Close to 100% Nitrate-to-Ammonia Selectivity

作者：Wanying Wang, Jiu Chen, Edmund C. M. Tse · 发表于：Journal of the American Chemical Society · 年份：2023 · DOI：10.1021/jacs.3c08084 · 被引用次数：176 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Advanced Photocatalysis Techniques、Caching and Content Delivery

Nitrate electroreduction (NO 3 RR) holds promise as an energy-efficient strategy for the removal of toxic nitrate to restore the natural nitrogen cycle and mitigate the adverse impacts caused by overfertilization from suboptimal agricultural practices. However, existing catalysts suffer from limited electrocatalytic activity, poor selectivity, inadequate durability, and low scalability. To address this quadrilemma, in this study, we developed a cost-effective layered double hydroxide (LDH) electrocatalyst with a lamellar structure that presents trimetallic CuCoAl active sites on the nanomaterial surface. This codoping design enabled electrochemical upcycling of nitrate into ammonia exclusively and efficiently with an onset potential at 0 V vs RHE, where the electrocatalytic process is less energy intensive and has a lower carbon footprint than conventional practices. The synergistic interaction among Cu, Co, and Al further afforded a 99.5% Faradic efficiency (FE) and a yield rate of 0.22 mol h –1 g –1 for nitrate-to-ammonia electroreduction, surpassing the performance of state-of-the-art nonprecious metal NO 3 RR electrocatalysts over an extended operation period. To gain insights into the origin of the catalytic performance observed on LDH, control materials were employed to elucidate the roles of Cu and Co. Cu was found to improve the NO 3 RR onset potential despite displaying limited FE for ammonia synthesis, while Co was discovered to suppress the formation of nitrite byp...