Oxygen-Mediated Hydrogen Spillover Promotes Stable Synthesis of Vinyl Chloride on Ru Single-Atom Catalysts

Ru single-atom catalysts hold great promise for the robust synthesis of vinyl chloride through acetylene hydrochlorination. However, the easy over-chlorination of Ru atoms during reaction suppress the catalytic activity and stability. Herein, we have synthesized an oxygen doped Ru single-atom catalyst by a sequential oxygen etching strategy, which delivers the remarkable yield of vinyl chloride monomer (>99.38 %) and stability (>900 h, 180 h^-1), far beyond those reported Ru counterparts. Experimental results and theoretical calculations reveal that the asymmetric structure of single-atom Ru promotes an unconventional oxygen-mediated hydrogen spillover after the activation of hydrogen chloride, which enables the reaction to proceed through Eley-Rideal mechanism with a reduced energy barrier of acetylene hydrochlorination compared to the traditional Langmuir-Hinshelwood pathway. As a result, the enhanced reaction kinetics further restrict over-chlorination of single-atom Ru, thereby ensuring the excellent durability. This work offers a strategy for designing multifunctional catalysts with enhanced performances for acetylene hydrochlorination.