VOX/Al2O3 Catalyzed Oxidative Dehydrogenation of Propane: Focus on Catalyst Characterization and Deactivation Behavior

Oxidative dehydrogenation of hydrocarbons (ODH) converts propane and/or ethane into propylene and/or ethylene, which are important compounds in the chemical industry. Unlike steam cracking, ODH offers a high theoretical conversion to olefins and lower energy consumption. The ODH reaction of propane to propylene was studied using VO_X/Al₂O₃ catalysts prepared by wet impregnation. The reaction conditions were widely varied, with temperatures ranging from 300 to 550 °C, the C₃/O₂ ratio from 1.6 to 3.3, and the vanadium content from 1 to 11 wt %. It was observed that these parameters are key experimental variables that influence the performance of the catalysts in ODH. Catalysts with intermediate vanadium loading exhibit an optimal amount of acidic sites due to the presence of monomeric and polymeric VO_X species, resulting in high selectivity toward propylene. Temperature-programmed oxidation analyses showed that coke deposition is proportional to the degree of VO_X polymerization.