CuO@TiO2 Hollow Cubes Enable Highly Selective and Stable Photocatalytic Non‐Oxidative Methane Coupling to Ethylene

Abstract Photocatalytic non‐oxidative coupling of methane (PNOCM) provides a green and sustainable route to the synthesis of ethylene (C 2 H 4 ). TiO 2 intrinsically can activate CH 4 through photogenerated holes. However, taking advantage of this property for highly selective C 2 H 4 production remains a significant challenge. Herein, CuO nanoparticles loaded hollow cubic TiO 2 (CuO@hcTiO 2 ) nanoparticles are synthesized via hydrolytic‐crystallization constrained morphology engineering combined with a chemical precipitation method. It exhibited an outstanding C 2 H 4 selectivity of 97.7% and a production efficiency of 3937.2 µmol g −1 CuO h −1 , with excellent stability reaching 30 h. Compared with reported TiO 2 based photocatalysts, the selectivity of C 2 H 4 from CuO@TiO 2 increased by 2~20 fold. Mechanistic investigations suggest that CuO nanoparticles loaded on TiO 2 act as active sites for * CH 3 capture due to the partially filled d orbitals. And the type‐I heterojunction between CuO and TiO 2 promotes photogenerated holes migration from TiO 2 to the CuO, facilitating the dehydrogenation of adsorbed * CH 3 to * CH 2 and subsequent coupling to C 2 H 4 . This work provides a promising strategy for designing photocatalysts to efficiently synthesis C 2 H 4 via PNOCM.