Hollow multishelled spherical PrMnO3 perovskite catalyst for efficient catalytic oxidation of CO and toluene

For the first time, hollow multishelled spherical PrMnO3 perovskite (PrMnO3-HoMSs) are successfully prepared and applied to catalytic CO and toluene oxidation. The shells of PrMnO3-HoMSs present porous and polycrystalline features, achieving a high specific surface area. Compared with the samples (PrMnO3-CP) synthesized by the traditional co-precipitation method, PrMnO3-HoMSs exhibits higher catalytic performance for both CO and toluene oxidation. The activation energies of catalytic CO and toluene oxidation over PrMnO3-HoMSs are 27.4 and 113.1 kJ/mol, respectively. Based on Raman and H2-TPR results, there are some vacancy-doped Pr1−xMnO3+δ in both samples, and the extraction of some Pr species from the perovskite phase facilitates the generation of lattice vacancies and increases the content of Mn4+ species, as proven by XPS, H2-TPR and O2-TPD characterization. The high molar ratio of Mn4+/Mn3+, improved low-temperature reducibility and increased content of active oxygen species are responsible for the excellent catalytic activity of PrMnO3-HoMSs. Moreover, PrMnO3-HoMSs exhibits good thermal durability due to the mutual support of multiple shells. Taking its excellent catalytic activity and thermal stability into consideration, we believe that the hollow multishelled spherical PrMnO3 catalyst is a good candidate for eliminating CO and toluene.