A growing demand exists for highly efficient photothermal catalysts for the oxidation of volatile organic compounds (VOCs). This study demonstrated the enhanced light-driven photothermal oxidation of toluene over plasmonic CuOx-WOx bimetallic oxides supported on titanium-modified Ultra stable Y (USY) zeolite (yCuOx-WOx/mTiO2-x-USY). In a reaction stream containing 200 ppm toluene concentration and 5 vol% H2O, the optimized 20CuOx-WOx/mTiO2-x-USY achieved 90.4% toluene conversion and 82.0% CO2 yield at a surface temperature of 235 oC which is higher than that achieved by WOx/mTiO2-x-USY (73.9% and 52.6%) at a surface temperature of 233 oC under the full light intensity of 500 mW/cm2. The introduction of CuOx and WOx metal oxides on a titanium modified USY surface resulted in efficient photon absorption and heat generation under full light irradiation. Additionally, in situ DRIFTS analysis indicated that the novel CuOx-WOx synergy improved the activation of oxygen, toluene molecules and mobility of oxygen species. The CuOx d-band centers promoted the adsorption of molecular oxygen and cleavage of the oxygen-oxygen bond while the presence of Cu+-Cu2+ and W5+-W6+ redox sites was vital for the continuous Mars-van Krevelen mechanism. This study provides insights into the functionality of plasmonic bimetallic nanomaterials as outstanding candidates for the light-driven photothermal degradation of VOCs.
Efficient UV-vis-IR light-driven photothermal oxidation of toluene over CuOx-WOx/mTiO2-x-USY promoted by the CuOx-WOx synergy.