High‐Loading Ag Single Atoms Anchored on MoS 2 Nanosheet Aggregates Enable Synergistic Nitrate‐to‐Ammonia Electroconversion

ABSTRACT Electrocatalytic nitrate reduction (NO 3 RR) to ammonia (NH 3 ) offers a sustainable route for coupling nitrate (NO 3 − ) remediation with NH 3 synthesis. However, its efficiency is often limited by the insufficient NO 3 − activation, incomplete hydrogenation of nitrogen‐containing intermediates, and the competing hydrogen evolution reaction (HER). Herein, we report a catalyst consisting of Ag single atoms anchored on flower‐like MoS 2 nanosheet aggregates (Ag‐MoS 2 NAs) for efficient NO 3 − ‐to‐NH 3 conversion. Ag‐MoS 2 NAs feature a high loading of isolated Ag sites while preserving atomic dispersion, providing abundant NO 3 − activation centers. During NO 3 − ‐to‐NH 3 conversion, Ag sites promote NO 3 − adsorption and initial deoxygenation steps, whereas MoS 2 provides active hydrogen species for the subsequent hydrogenation of nitrogen‐containing intermediates. The integration of these complementary functions enables efficient NO 3 − activation and subsequent hydrogenation, thereby enhancing NH 3 production and achieving a Faradaic efficiency of up to 95%. As a result, the Ag‐MoS 2 NAs maintain stable operation for over 200 h at current densities exceeding 400 mA cm −2 , achieving an NH 3 yield rate of 30.6 mg h −1 cm −2 . This work demonstrates that integrating NO 3 − activation sites with hydrogenation functionalities in a single catalyst can effectively promote NH 3 production from NO 3 − under industrially relevant conditions.