Tuning the Metal–Support Interaction by Modulating CeO₂ Oxygen Vacancies to Enhance the Toluene Oxidation Activity of Pt/CeO₂ Catalysts

Abstract

In this research, a range of Pt/CeO 2 catalysts featuring varying Pt−O−Ce bond contents were developed by modulating the oxygen vacancies of the CeO 2 support for toluene abatement. The Pt/CeO 2 −HA catalyst generated a maximum quantity of Pt−O−Ce bonds (possessed the strongest metal− support interaction), as evidenced by the visible Raman results, which demonstrated outstanding toluene catalytic performance. Additionally, the UV Raman results revealed that the strong metal− support interaction stimulated a substantial increase in oxygen vacancies, which could facilitate the activation of gaseous oxygen to generate abundant reactive oxygen species accumulated on the Pt/ CeO 2 −HA catalyst surface, a conclusion supported by the H 2 -TPR, XPS, and toluene-TPSR results. Furthermore, the results from quasi-in situ XPS, in situ DRIFTS, and DFT indicated that the Pt/ CeO 2 −HA catalyst with a strong metal−support interaction led to improved mobility of reactive oxygen species and lower oxygen activation energies, which could transfer a large number of activated reactive oxygen species to the reaction interface to participate in the toluene oxidation, resulting in the relatively superior catalytic performance. The approach of tuning the metal−support interaction of catalysts offers a promising avenue to develop highly active catalysts for toluene degradation.