Probing toluene catalytic removal mechanism over supported Pt nano- and single-atom-catalyst

Commercial TiO2 supported 0.20 wt% Pt catalyst is obtained via the molten salt method, and both Pt nanoparticles and single atom Pt sites are observed. It exhibits high catalytic performance for toluene oxidation, with T50 and T90 being 173 and 183 °C, respectively. Reaction intermediates including benzene, p-xylene, o-xylene, benzaldehyde, phthalic acid, maleic anhydride, itaconic anhydride, acetone, and acetic acid, are detected during toluene oxidation. On this basis, likely toluene combustion reaction pathway is provided. Benzaldehyde is the most stable surface intermediate, and its oxidation can be rate-limiting for the entire toluene oxidation reaction. 2-10.0 vol% H2O slightly inhibits the reaction by competing surface sites with the reactant, while it does not poison the catalyst. 2.5-10.0 vol% CO2 slightly poisons the catalyst by surface carbonate formation, whereas 50 ppm SO2 severely poisons the catalyst by sulfite/sulfate formation.