Diverse Effects of SO2-Induced Pt-O-SO3 on the Catalytic Oxidation of C3H6 and C3H8.

The effects of sulfur dioxide (SO2) in the catalytic purification of short-chain hydrocarbons are still controversial, and the exact role of SO2 on adsorption and reaction pathways during the catalytic oxidation of different volatile organic compounds (VOCs) remains unclear. Herein, a three-dimensional ordered macroporous Ce0.8Zr0.2O2 supported Pt nanoparticle monolithic catalyst (Pt/OM CZO) was synthesized to investigate these effects. Our findings uncover the diverse effects of SO2: Upon SO2 treatment, the coupling between the S 3p and Pt 5d orbitals promotes the Pt-O-SO3 structure in situ formed on the catalyst surface. The propene (C3H6) molecule readily binds with the oxygen atom in Pt-O-SO3, resulting in the accumulation of acetone and carbon deposition, thereby hindering C3H6 oxidation. Conversely, a cleaved oxygen atom within the Pt-O-SO3 structure enhances propane (C3H8) adsorption and activates the C-H bond, facilitating C3H8 oxidation. These insights are pivotal for advancing the frontier of sulfur-tolerant catalysts, addressing both economic and environmental challenges.