CeO2 Wetting Layer on ZrO2 Particle with Sharp Solid Interface as Highly Active and Stable Catalyst for HCl Oxidation Reaction

摘要

Dry impregnation of CeO2 on ZrO2 particles (CeO2@ZrO2) and calcination at 600 degrees C for 5 h result in a highly dispersed layer of the catalytically active CeO2 phase with an enriched concentration of Ce3+. The distinct morphology of CeO2@ZrO2 is responsible for the high (specific) activity in the gas-phase oxidation of HCl (Deacon reaction). Surprisingly, the CeO2@ZrO2 catalyst calcined at 600 degrees C is chemically even more stable toward chlorination under harsh Deacon condition than that calcined at 900 degrees C, where a solid solution of ZrO2 and CeO2 is formed at the solid interface. The improved stability of the CeO2 layer calcined at 600 degrees C is traced to its sharp interface formed with the ZrO2 support. We expect that this kind of active and stable layer morphology of CeO2 supported on ZrO2 is beneficial for other catalytic oxidation reactions as well, either as an active component or as a supporting material for another active metal component.