Ball-Milling Induced Debonding of Surface Atoms from Metal Bulk for Construing High-Performance Dual-Site Single-Atom...

One of the most pressing challenges in single-atom catalysis is the manipulation of the coordination environment of central metals to maximize the catalyst performance. Herein, we fabricated a high-performance catalyst (Co-SNC) by introducing S into the neighboring position of the Co-N₄ coordination. The developed ball-milling method enabled large-scale synthesis, that over 4.7 g of Co-SNC can be produced in one pot. In benzylamine coupling reaction, Co-SNC exhibited the highest conversion of 97.5 % with 99 % selectivity toward N-benzylidenebenzylamine in 10 h among various Co catalysts. Density functional theory calculations revealed the crucial role of S atoms, which serve as the active sites for O₂ activation, leaving the Co atoms free to adsorb benzylamine. Consequently, the adsorption energies of O₂ and benzylamine were significantly increased. Our strategy suggests a feasible approach to enhance catalytic performance by delicately integrating dual active sites into a single catalyst unit.