In Situ Generation of High‐Loading Asymmetric Metal Cluster Catalysts via 2D Confinement for Enhanced Electrocatalysis

Abstract Fully exposed atomically dispersed metal cluster (ACs) catalysts offer near‐100% atom utilization and exceptional catalytic activity, yet achieving high loading and controlled synthesis remains challenging. To address this issue, leveraging high‐temperature calcination of porous C 2 N and its inherent 2D confinement effect, asymmetric 3d metal clusters are in situ anchored within cavity centers (asymmetric MACs/C 2 N), yielding high‐loading (12.8 wt.%), fully exposed asymmetric Cu ACs. For the model nitrate reduction (NO 3 RR), CuACs/C 2 N exhibit exceptional catalytic performance, achieving a Faradaic efficiency of 97.9% and an NH 3 yield of 0.66 mg h −1 cm −2 at −0.6 V. Spectroscopic analysis and theoretical calculations indicate that the dynamic evolution of the asymmetric Cu 5 N 2 active sites during the reaction significantly lowers the reaction energy barrier. This strategy is further applicable to 4d palladium‐ and 5d platinum‐based systems (PdACs/C 2 N, PtACs/C 2 N), demonstrating its broad potential. The development of high‐loading asymmetric atomic clusters offers a novel and effective approach for constructing highly active catalytic sites in advanced electrocatalysts.