Oxidative Dehydrogenation of Propane over Mechanochemically Activated V2O5-Cr2O3 System

High-energy ball milling of V2O5-Cr2O3 mixture (V/Cr molar ratio = 1/10) initially causes dispersion of vanadium oxide on the surface of chromium oxide grains resulting in an active phase-support system. The increase of both, the V/Cr ratio on the surface and acidity of active sites is observed. Thus, this system mechanically treated for only 30 minutes has lower selectivity of propane conversion to propylene than the non-milled one. Due to homogenization resulting from longer milling time, the vanadium layer on the surface is destroyed and therefore the lower V/Cr ratio on the surface and decrease in acidity are observed. Simultaneously, the formation of Cr2VO5.5 phase takes palce. It was concluded that these phenomena were responsible for a significant increase of selectivity in conversion of propane to propylene in contrast to the non-activated sample.