Dual-templating fabrication of three-dimensionally ordered macroporous ceria with hierarchical pores and its use as a support for enhanced catalytic performance of preferential CO oxidation

In this study, several three-dimensionally ordered macroporous (3DOM) CeO2 having hierarchical pore structure were successfully prepared via a dual ‘hard-soft’ templating strategy using Ce(NO3)3·6H2O containing phenol-formaldehyde (PF) resol or/and sucrose as the ceria precursor. The resulting CeO2 samples were characterized by N2 adsorption-desorption analysis, scanning electron microscopy, transmission electron microscopy and X-ray diffraction, which showed that the hierarchical 3DOM CeO2 possessed interconnected networks of the ordered macropore structures with large mesopores, and both the BET surface area and pore volume increased significantly compared with the conventional 3DOM CeO2. The improved textural parameters should be attributed to the emergence of mesopores in the interconnected three-dimensional skeleton, which were formed by oxidative removal of carbon produced from carbonization of PF resol or sucrose. The hierarchical 3DOM CeO2 exhibited a superior performance to the conventional 3DOM or bulk CeO2 when used as supports for Ir catalysts in preferential CO oxidation.