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

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.