Enhanced photocatalytic performance for nonoxidative coupling of methane over FeOx cluster decorated TiO2

Abstract

Photocatalytic nonoxidative coupling of methane (NOCM) is a meaningful route to obtain multicarbon compounds but faces considerable challenges due to the inertness of methane and poor C–C coupling ability of active sites. Herein, we report an FeO_x cluster-decorated TiO₂ photocatalyst for an efficient photocatalytic NOCM reaction. The results show that decoration of FeO_x clusters over TiO₂ enables adsorption of CH₄ to proceed without thermodynamic limitation, thus being conducive to the conversion of CH₄. Besides, FeO_x clusters contribute to stabilizing lattice oxygen via increasing the bonding energy barrier between *CH₃ and lattice oxygen, thus alleviating the formation of CO₂ and ultimately improving C₂H₆ selectivity. The optimized 0.2FeO_x/TiO₂ exhibits a high C₂H₆ generation rate of 91.0 μmol g⁻¹ h⁻¹ (16.9 times that of bare TiO₂) with a C₂H₆ selectivity of 81.7%. The outcome is meaningful for the design and fabrication of low-cost photocatalysts with high catalytic performance for the photocatalytic NOCM reaction.