Co3O4 supported on CeO2 with specific morphologies for high efficient CO-PROX reaction

In order to investigate the effect of morphology of CeO2 supports on Co3O4/CeO2 catalysts for CO selective oxidation in H2-rich stream, the CeO2 nanorods (CeO2-NR), CeO2 nanoplates (CeO2-NP) and CeO2 nanowires (CeO2-NW) are controllable synthesized via hydrothermal methods. Characterization results reveal that the morphologies of CeO2 play an important role for the exposure of crystal facet. The CeO2-NP with more (111)-exposed facets containing the highest concentration of Ce3+ and oxygen vacancies, which provides a prerequisite to process better catalytic activity. In addition, the smaller crystallite size of CeO2-NP favors the larger BET surface area of the catalyst, which contributes to the fine dispersion of Co3+ species catering CO adsorption and oxidation and enhancing CO-PROX activity. The Co3O4/CeO2-NP catalyst is observed the maximum CO conversion rate (99.6%) and the O2 selectivity 79.6 % at 200 ℃. This finding highlights the importance of morphology of CeO2 supports for improving catalytic activity.