High Sulfur-Tolerant Pt/TiO2 for Catalytic Complete Oxidation of Toluene

Abstract

The SnO₂ doped 0.2 wt % Pt/TiO₂ catalysts were prepared by wet impregnation method for the catalytic oxidation of toluene. The research focused on the SO₂ resistance and catalytic performance of Pt/SnO₂–TiO₂. The results showed that T₉₀ (the temperature corresponding conversion of 90%) was 176°C at 1000 ppm toluene concentration and weight hourly space velocity (WHSV) of 36 000 mL h^–1 g^–1. Adding 10 wt % SnO₂ to the Pt/TiO₂ catalyst reduced the adsorption capacity of the active component Pt for SO₂, enhancing the catalyst’s resistance to SO₂ poisoning. Pt/SnO₂–TiO₂ catalysts could recover to the initial activity after 9 h poisoning with 2800 ppm thiophene. The Pt/SnO₂–TiO₂ also maintained good stability during the 60 h test at 240°C with a toluene conversion larger than 99%. A series of characterization tests including XRD, H₂-TPR, and TEM revealed that Pt/SnO₂–TiO₂ possesses a mesoporous structure and a large amount of lattice oxygen, with Pt being uniformly dispersed on the carrier surface.