Enhanced photothermal catalytic degradation of toluene by loading Pt nanoparticles on manganese oxide: Photoactivation of lattice oxygen

Light-driven photothermocatalysis can provide enough energy to reach light-off temperature of VOCs on the surface of catalyst without auxiliary heat source. Herein, we synthesized noble-metal supported manganese oxide catalysts (xPt/MO) and studied their photothermal catalytic behavior of toluene degradation, where 1 Pt/MO (1 wt.% loading of Pt) and 2 Pt/MO (2 wt.% loading of Pt) exhibited more than 90 % of conversion and 70 % of mineralization under illumination of 200 mW/cm2 light intensity with a value of 30,000 mL/(g·h) for weight hourly space velocity (WHSV), respectively. Comparison to pure MO, 1 Pt/MO owns a good photothermal catalytic stability for at least 60 h without obvious deactivation. The introduction of Pt promotes the crystallization of MO (verified by XRD and TEM analysis) and enhances the mobility of surface/sub-surface lattice oxygen (verified by O2-TPD, H2-TPR and CO consumption). It is proved that illumination not only supplies thermal energy to trigger the reaction of toluene oxidation but also further evoke more lattice oxygen on Pt/MO to participate in toluene decomposition.