Steering C-H Activation by Spin-Polarized Single-Sites for Near-Unity Selective and Efficient Photocatalytic Methanol Coupling to Ethylene Glycol.

Photocatalytic methanol coupling holds great promise for the sustainable production of value-added ethylene glycol (EG) and hydrogen yet remains challenging due to the difficulty in achieving selective C-H activation associated with spin-state transitions. Here, we develop a spin-polarized photocatalyst (-Mo/ZCS) by anchoring asymmetric spin-state Mo single-sites onto ZnCdS, enabling selective C-H activation through quantum spin exchange interactions. Consequently, it demonstrates exceptional EG selectivity (97.6%), yield (236.2 mmol g), turnover number (1417.2 mol mol), and catalytic durability (over 100 h) in photocatalytic methanol coupling, with the EG production rate outperforming standalone ZnCdS by over an order of magnitude. We reveal that the spin-polarized Mo single-sites enhance surface polarization, thereby accelerating charge-carrier separation and migration. More importantly, they facilitate the spin-state transition of C-H activation to generate CHOH and the subsequent C-C coupling, consequently improving the selectivity and efficiency of EG synthesis. This study highlights the pivotal role of spin-implantation in steering C-H activation for efficient photocatalytic methanol coupling and related reactions.