Low content of CoOx supported on nanocrystalline CeO2 for toluene combustion: The importance of interfaces between active sites and supports

Abstract A low content of CoO x (1 wt% Co loading) was deposited on CeO 2 nanoparticles (CoCe-P), nanorods (CoCe-R) and nanocubes (CoCe-C) for toluene oxidation. The CoCe-P catalyst showed a significantly higher activity than CoCe-R or CoCe-C. Compared with CoCe-C, the temperature of toluene conversion (T 90  = 90% and T 50  = 50%) for CoCe-P decreased by ΔT 90  = 86 °C and ΔT 50  = 60 °C. The reaction rate (r, mol m −2  s -1 ) of the CoCe-P catalyst at 220 °C increased by nine times. The low content of CoO x formed as either nanoparticles or highly dispersed species on the surfaces of different CeO 2 nanostructures. The different interactions between CoO x and CeO 2 are intrinsically relevant to the various redox and catalytic properties. There exists a synergistic effect at the interface between CoO x and CeO 2 . Highly dispersed CoO x species and the increased oxygen vacancies at the interface led to the excellent performance of CoCe-P for toluene oxidation.