Light-driven photothermal catalytic oxidation of toluene over CuOx-WOx/mTiO2−x-USY: Revealing CuOx-WOx synergy

Abstract

Light-driven photothermal catalytic oxidation is a promising strategy for sustainable volatile organic compounds (VOCs) elimination. Herein, we report the construction of yCuOx-WOx/mTiO2−x-USY nanocomposite (y = Cu weight percentage and x represents oxygen ratio in metal oxides due to the mixed-valence metal, USY = ultrastable Y zeolite) for the degradation of toluene. Combining both CuOx and WOx metal oxides on the mTiO2/USY induced strong light absorption, improved oxygen mobility, and good catalytic activity. Among the catalysts, the optimized 20CuOx-WOx/mTiO2−x-USY exhibits the highest light-driven catalytic performance of 90.4% toluene conversion and 82.0% CO2 yield at a surface temperature of 235 oC under full light irradiation with an optical intensity of 500 mW/cm2. The existence of a CuOx-WOx synergy amplified the capture of light energy, heat generation, and molecular oxygen activation. Impressively, the catalyst demonstrated satisfactory stability during long-term application. Furthermore, in situ DRIFTS analysis suggested benzoate species as major reaction intermediates.