Novel nanowire self-assembled hierarchical CeO2 microspheres for low temperature toluene catalytic combustion

•The hierarchical microsphere CeO2 (CeO2-HS) is prepared.•The CeO2-HS is self-assembled by many ceria nanowires.•The CeO2-HS exhibits the outstanding activity toward toluene catalytic oxidation.•Surface oxygen vacancies control the reaction rate.

The catalytic oxidation of toluene has been investigated over pure CeO2 hierarchical catalyst for the first time. The novel CeO2 catalyst was prepared by a hydrothermal-driven assembly method. The structure of CeO2 catalyst was consisted of nanowire self-assembled hierarchical microspheres. The new hierarchical CeO2 catalyst showed much better catalytic activity than analogous nonporous catalyst by traditional hydrothermal method. The hierarchical CeO2 catalyst could reach more than 90% toluene conversion even as low as 210 °C (T90) under a high space velocity of 60,000 mL/(g·h). The high catalytic activities could be attributed to the large surface areas, in addition, the hierarchical porous structures provide more contents of surface oxygen vacancies for the dissociation of gaseous O2 on the surface.

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