Oxygen vacancy promoted C–H activation enhancing hydrogenolysis of polyethylene plastics over Ru/CeO2 catalyst

Catalytic hydrogenolysis offers a promising route for plastic waste upcycling. Herein, we demonstrate that oxygen vacancies (O V ) in CeO 2 supports dramatically enhanced this process. Reduction-engineered Ru/CeO 2 -NH 3 -800 exhibits 40% higher activity at 800 °C than untreated counterparts. Comprehensive characterization revealed unchanged Ru metal sites after treatment, but significantly increased oxygen vacancy content in the CeO 2 support. Isotopic C 6 –D 2 temperature-programmed surface reaction studies revealed that higher O V concentrations correlate with lower C–H bond activation temperatures, directly aligning with observed activity trends. We propose a novel Ru–Ce interfacial mechanism: O V -adjacent Ce 3+ –O sites activate C–H bonds to form *RCCR* intermediates, while dual Ru sites cleave C–C bonds via C–Ru coordination. This work establishes an O V -driven structure-activity relationship for the first time and reveals support-mediated C–H activation as crucial for advanced catalyst design.