A novel 3DOM Pt/MeOx–SiO2 catalyst for the catalytic oxidation of VOCs

Abstract

In this work, we utilized three-dimensional ordered macroporous (3DOM) SiO₂ and non-noble metal oxides (CeO_x, CoO_x and MnO_x) to confine highly dispersed Pt species. The 3DOM Pt/MeO_x–SiO₂ catalyst was used for the catalytic oxidation of benzene to evaluate its catalytic activity, long-term thermal stability, sulfur resistance, and water resistance. The results verified that the 3DOM Pt/CeO_x–SiO₂ catalyst had superior activity (T₉₀ = 210 °C) and strong sulfur resistance (10 ppm). Interestingly, we observed that the 3DOM Pt/MnO_x–SiO₂ catalyst exhibited poor activity and strong sulfur resistance, while the 3DOM Pt/CoO_x–SiO₂ catalyst exhibited poor sulfur resistance. The comprehensive characterizations results indicated that the activity of the catalysts was ascribed to the interaction of MeO_x and Pt species, and the strong interaction of CeO_x and Pt species was beneficial for improving the dispersion of Pt and enriching the surface acid sites and active oxygen and Pt⁰ species. In contrast, the poor interaction of MnO_x/CoO_x and Pt species was unfavourable for the dispersion of Pt, active oxygen species and the surface acidity of the catalysts. In particular, the poor sulfur resistance of 3DOM Pt/CoO_x–SiO₂ was related to the content of Pt^&+ with a high chemical valence state.