Mass production of Co3O4@CeO2 core@shell nanowires for catalytic CO oxidation

In this study, Co 3 O 4 @CeO 2 core@shell nanowires were successfully prepared via thermal decomposition of Co(CO 3 ) 0.5 (OH)·0.11H 2 O@CeO 2 core@shell nanowire precursors. As a CO oxidation catalyst, Co 3 O 4 @CeO 2 shows remarkably enhanced catalytic performance compared to Co 3 O 4 nanowires and CeO 2 nanoparticles (NPs), indicating obvious synergistic effects between the two components. It also suggests that the CeO 2 shell coating can effectively prevent Co 3 O 4 nanowires from agglomerating, hence effecting a substantial improvement in the structural stability of the Co 3 O 4 catalyst. Furthermore, the fabrication of the well-dispersed core@shell structure results in a maximized interface area between Co 3 O 4 and CeO 2 , as well as a reduced Co 3 O 4 size, which may be responsible for the enhanced catalytic activity of Co 3 O 4 @CeO 2 . Further examination revealed that CO oxidation may occur at the interface of Co 3 O 4 and CeO 2 . The influence of calcination temperatures and the component ratio between Co 3 O 4 and CeO 2 were then investigated in detail to determine the catalytic performance of Co 3 O 4 @CeO 2 core@shell nanowires, the best of which was obtained by calcination at 250 °C for 3 h with a Ce molar concentration of about 38.5%. This sample achieved 100% CO conversion at a reduced temperature of 160 °C. More importantly, more than 2.5 g of the Co 3 O 4 @CeO 2 core@shell nanowires were produced in one pot by this simple process, which may be beneficial for practical applications as automobile-exhaust gas-treatment catalysts.