Highly active and stable mesoporous Au/CeO2 catalysts prepared from MCM-48 hard-template

摘要

Mesoporous CeO2 nanoparticles were synthesized through a hard-template approach using MCM-48. After removal of silica by hot NaOH solution, the obtained mesoporous CeO2 was a reverse-replica of the porosity structures of MCM-48. Compared to nanocrystalline CeO2 powder prepared by alkaline precipitation, the mesoporous CeO2 samples were smaller in particle size and much larger in surface area and in proportion of surface oxygen reducible at low temperature. The gold catalysts supported on the mesoporous CeO2 exhibited high catalytic activity and stability in benzene oxidation. Complete conversion of 0.5% benzene in air to carbon dioxide could be achieved at 200 °C and high benzene conversion was maintained at 220 °C in a test of 50-h duration whereas, a gold catalyst supported on normal ceria powder suffered severe deactivation due to gold sintering when tested under the same condition.