Spatial Decoupling of Adsorption and Transformation Sites on Ag‐Cu Dual‐Single‐Atom Catalysts for Highly Selective Photocatalytic Nitrate‐to‐Ammonia Reduction

作者：Zichao Lian, Di Luo, Jiarui Yang, Yupeng Yang, S. Q. Tang, Hao Li, Dieqing Zhang, Hexing Li · 发表于：Angewandte Chemie International Edition · 年份：2025 · DOI：10.1002/anie.202516964 · 被引用次数：14 · 研究领域：Advanced Photocatalysis Techniques、Ammonia Synthesis and Nitrogen Reduction、Nanocluster Synthesis and Applications

Abstract Photocatalytic nitrate (NO 3 – ) reduction to ammonia (NH 3 ) presents a sustainable solution for simultaneous NH 3 synthesis and wastewater remediation. However, achieving high selectivity is challenging, plagued by sluggish kinetics and parasitic side reactions. In this study, we rationally design a synergistic Ag‐Cu dual‐atom catalyst on g‐C 3 N 4 (AgCu‐CN) that embodies a spatially decoupled tandem scheme. We demonstrate that the oxophilic Cu 1 site serve as Lewis acid centers to efficiently capture and activate NO 3 – , before the crucial *NO intermediate is shuttled to adjacent Ag 1 site, which is intrinsically inert toward the hydrogen evolution reaction, act as dedicated hydrogenation center for rapid and deep *NO reduction. This atomic‐level synergy manifests in a state‐of‐the‐art performance, with AgCu‐CN delivering an impressive 98% NH 3 selectivity and a production rate of 630.5 µmol h −1 g −1 under visible light. In situ spectroscopic studies and theoretical calculations corroborate the tandem mechanism and the critical role of the Ag‐Cu dual sites in steering reaction selectivity. This study establishes a powerful tandem catalytic design principle to manage the selectivity challenges in complex multi‐proton/electron reactions.