Constructing Asymmetric Dual Active Sites Through Bimetallic Synergy for Achieving Selective Photocatalytic Nonoxidative Coupling of Methane toward Ethylene

Photocatalytic nonoxidation coupling of methane reactions can directly convert methane into high-value C2 products under mild conditions. However, the efficient conversion of CH4 to C2H4 is severely limited by the high C–H bond energy of CH4 and the slow kinetic process of C–C coupling. Herein, Mo-WO3–x catalysts with dual active sites were constructed by the isomorphic substitution of Mo6+ for W in WO3. Among them, Mo doping not only induces the preferential formation of oxygen vacancies between Mo and W atoms, but also enhances the catalytic activity of frustrated Lewis pairs composed of unsaturated W and lattice oxygen. The results show that the asymmetric dual active sites of unsaturated Mo and FLPs accelerate the cleavage of CH4 molecules, reduce the coupling energy barrier of CH2 intermediates, and synergistically promote the desorption of C2H4. The catalyst presents a C2H4 yield of up to 152.19 μmol g–1 h–1 with a selectivity of 95%. This work provides insights into the preparation of highly efficient NOCM photocatalysts with a bimetallic synergistic effect.