Photocatalytic ethylene production over defective NiO through lattice oxygen participation

Lattice oxygen-mediated photocatalytic ethane dehydrogenation represents a sustainable strategy for ethylene production, yet achieving a balance between high productivity, selectivity, and durability remains challenging. Here, we report a defective NiO-300 catalyst, where precisely engineered Ni vacancies activate lattice oxygen by weakening Ni-O bond and improving lattice oxygen mobility. This promotes efficient ethane activation and C-H bonds cleavage through photoinduced hole capture, intensifying ethane dehydrogenation via a light-boosted Mars-van Krevelen mechanism. The NiO-300 catalyst manifests a high ethylene yield of 604.5 μmol g^-1 h^-1 with 100% selectivity and stability over 200 cycles. In situ spectroscopic and theoretical studies elucidate the generation of active oxygen species, the evolution of Ni coordination, the formation of key intermediates, and the underlying photocatalytic mechanism. Our findings highlight cation vacancy engineering as a powerful tactic to fully activate lattice oxygen for solar-driven alkene production from alkane dehydrogenation over oxide photocatalysts.