Crystallography and porosity effects of CO conversion on mesoporous CeO2

Catalytic properties and thermal stability were studied for samples of mesoporous ceria with different BET specific surface area. The catalytic conversion of carbon monoxide to carbon dioxide and how thermal treatments of the catalysts influence the catalytic properties have been investigated. The materials were studied by transmission electron microscopy and by conversion profile measurements of CO versus temperature using a plug flow micro reactor made in quartz glass only. In order to compare the catalytic properties associated with a specific structure or morphology directly, aliquots of surface area (0.6 m(2)) of the catalyst was used. Scanning electron microscopy and X-ray energy-dispersive spectrometry (XEDS) were used for surface morphology studies and elemental analysis. It was found that the proportion of {100} surfaces determine the catalytic properties of the material and these surfaces become important at calcination temperatures between 773 and 973 K. The internal mesoporous structure is destroyed at calcination temperatures around 873 K. (C) 2004 Elsevier Inc. All rights reserved.