Hierarchically porous silica supported ceria and platinum nanoparticles for catalytic combustion of toluene

Abstract The hierarchically porous silica (NKM-5) was synthesized by the polyelectrolyte-surfactant mesomorphous complex templating method, and the NKM-5 was used as the carrier to load different amounts of ceria to prepare xCe/NKM-5 samples (x represents the CeO2 loading amount) by the impregnation method, and then supported Pt to prepare Pt/xCe/NKM-5 catalyst for toluene catalytic combustion. NKM-5 sample has excellent specific surface area and pore structure, with the increase of CeO2 loading amount, the specific surface area and pore volume of xCe/NKM-5 sample decreased gradually. As the CeO2 loading amount increased, XRD and TEM characterization showed that the Pt dispersion of Pt/xCe/NKM-5 catalyst increased; XPS results showed that the proportion of Pt0 decreased and the proportion of Ce3+ increased; H2-TPR characterization showed that the reducibility increased; and the interaction between Pt and CeO2 increased gradually. The toluene catalytic combustion activity of Pt/xCe/NKM-5 catalyst first increased and then decreased with the increase of CeO2 loading amount. Pt/30Ce/NKM-5 catalyst has the most excellent catalytic activity with 50% toluene conversion at 174 °C and 90% conversion at 195 °C, which is the result of the synergy effect of the hierarchical pore structure of the support and the metal-support interaction between Pt and CeO2.