Size effect, mutual inhibition and oxidation mechanism of the catalytic removal of a toluene and acetone mixture over TiO2 nanosheet-supported Pt nanocatalysts

We prepare TiO2 nanosheet-supported Pt nanocatalysts with an average size of 1.3, 1.9, and 3.0 nm. Due to the great decrease in the adsorption ability for toluene and acetone, mutual inhibition is first observed over Pt1.9 nm/TiO2 for the catalytic removal of a toluene and acetone mixture. At 140 °C, the toluene and acetone reaction rate is 0.033 and 0.045 μmol/(gcat s), respectively, for the oxidation of 500 ppm toluene or acetone, which is much higher than the corresponding reaction rate (0.020 and 0.007 μmol/(gcat s)) for the oxidation of the mixture. Pt1.9 nm/TiO2 exhibits a good catalytic stability and H2O and CO2 tolerance. With strong evidence, we find that the co-presence of toluene and acetone does not change the catalytic mechanism, and the reaction pathway for the oxidative removal of toluene and acetone in the mixture may follow the pathway for the oxidation of single toluene or acetone.