Forked Vein Structure W/WO 3- x with Dual Active Sites in W and Oxygen Vacancies to Enhance Methylene Self-Coupling for Efficient Conversion of Methane to Ethylene.

The directional conversion of methane to ethylene is challenging due to the dissociation of the C─H bond and the self-coupling of methyl intermediates. Herein, a novel W/WO 3- x catalyst with the fork vein structure consisting of an alternating arrangement of WO 3- x and W is developed. Impressively, the catalyst achieves an unprecedented C 2 H 4 yield of 1822.73 µmol g -1  h -1 , with a selectivity of 82.49%. The enhanced catalytic activity is ascribed to the multifunctional synergistic effect induced by oxygen vacancies and W sites in W/WO 3- x . Oxygen vacancies provide abundant coordination of unsaturation sites, which promotes the adsorption and activation of CH 4 , thus reducing the dissociation energy barrier of the C─H bond. The CH 2 coupling barrier on the metal W surface is significantly lower compared to WO 3 , so CH 2 can migrate to the W site for coupling. Importantly, the W/WO 3- x with high periodicity provides multiple ordered local microelectric fields, and CH 2 intermediates with dipole moments undergo orientation polarization and displacement polarization driven by the electric field, thus enabling CH 2 migration. This work opens a new avenue for the structural design and modulation of photocatalysts, and provides new perspectives on the migration of methylene between multiple active sites.