Aprotic Solvent‐Mediated Microenvironment Engineering for Single‐Atom Catalysts Enables Selective Nitroarene Hydrogenation

ABSTRACT Single‐atom catalysts (SACs) have emerged as promising candidates for achieving exceptional activity and selectivity in diverse catalytic reactions. However, their synthesis often requires sophisticated techniques or reducing agents to combat metal atom aggregation. Herein, we report a straightforward synthesis of atomically dispersed Au 1 /COF SACs using acetone as an aprotic solvent to enable the direct anchoring of gold precursors onto imine‐bonded COFs. Solvent composition and precursor concentration are then systematically tuned to achieve controlled synthesis of Au species spanning single atoms to nanoparticles. Au 1 /COF SAC achieves a high gold loading of 2.53 wt.% and demonstrates excellent turnover frequency (5000 h −1 ) for the hydrogenation of p‐nitrophenol and high selectivity in the hydrogenation of various nitroarenes. Contrast experiments and density functional theory calculations indicate that the weak proton‐donating ability of acetone facilitates stepwise dechlorination of gold precursors, leading to stable Au‐N bonds through protonation of imine sites in COFs. Additionally, Au single‐atom sites facilitate preferential binding to the ‐NO 2 group, significantly enhancing the selectivity toward nitroarene hydrogenation. This work presents a simple synthetic strategy for SACs and provides a green and energy‐efficient approach for advanced COF‐based catalytic systems with potential for industrial applications.