Sol–Gel Assisted Preparation of Chromia–Silica Catalysts for Non-Oxidative Dehydrogenation of Propane

Preparation of continuous silica gel in the presence of dissolved Cr(NO 3 ) 3 leads to a hard high surface area (710 m 2 /g) microporous xerogel. Formation of the gel in the pore structure of mesoporous Pore-Expanded MCM-41 (PE-MCM-41) and macroporous commercial Cab–O–Sil silica results in retention of the mesoporous structure in the case of PE-MCM-41, and the formation of a powder with a broad pore size distribution in the case of Cab–O–Sil silica. Comparison of the catalytic activities in non-oxidative dehydrogenation of propane revealed a linear correlation of the initial conversion with the surface area for all three samples. The sample prepared from PE-MCM-41 through a sol–gel assisted procedure was the most active, particularly with respect to the catalysts prepared by simple wet impregnation with chromium nitrate.