DFT‐Guided Design and Synthesis of Bipyridine‐Anchored Copper Single‐Atom Catalysts for Efficient Nitrate‐to‐Ammonia Electroreduction Across a Broad pH Range

Abstract

Abstract The electrochemical conversion of nitrate to ammonia represents an efficient approach to alleviate nitrate pollution, concurrently providing a sustainable strategy for ammonia synthesis. The development of cost‐effective electrocatalysts that exhibit both high activity and selectivity in nitrate reduction reaction (NO 3 RR) constitutes a substantial challenge. Herein, we demonstrate the rational design of single‐atom catalysts (SACs) for the NO 3 RR through theoretical screening and precise synthesis techniques. A series of bipyridine‐anchored 3 d transition metal SACs has been computationally pre‐evaluated for their NO 3 RR activity and selectivity, and bipyridine‐Cu SAC stands out as the optimal candidate. Guided by the computational predictions, the bipyridine‐Cu encapsulated inside a zirconium‐containing metal–organic framework (namely Cu‐SA/UiO‐bpy) is synthesized and achieves an impressive ammonia yield rate of 7.4 mg NH3 h −1 cm −2 and a faradaic efficiency of 98.1% in NO 3 RR under neutral conditions. Additionally, Cu‐SA/UiO‐bpy exhibits remarkable catalytic performance (FE > 90%) across a wide pH range. In situ characterizations and theoretical calculations further reveal that bipyridine‐Cu sites facilitate the interfacial dissociation of water and the efficient generation of reactive hydrogen species, enabling the selective hydrogenation of NO x intermediates into ammonia. This integration of a data‐driven approach with precise synthesis presents a novel paradigm for developing high‐performance catalysts toward NO 3 RR and other catalytic applications.