CO2-oxidative Dehydrogenation of Light Alkanes Catalyzed by Cr Catalysts Supported on Different Mesoporous Silica Structures

Abstract Herein, a series of highly porous and well-structured mesoporous materials are presented as supports for chromium catalysts for the mild oxidative dehydrogenation of propane using CO 2 as the oxidizing agent. The materials MCM-41, SBA-1, and SBA-15 were proposed as supports for the preparation of Cr-based catalysts with a Cr content of 6 wt%. These results highlight that mesostructured supports influence chromium species’ dispersion and electronic state in the catalysts. Among the catalysts tested, the Cr/SBA-1 catalyst demonstrated superior propane conversion and propylene selectivity. The results suggest that the Cr 6+ species fraction significantly influences the conversion and selectivity during oxidative dehydrogenation of propane by CO 2 . As the Cr 6+ species fraction increases, a linear increase in conversion was observed for both propane and CO 2 . Furthermore, an increase in the Cr 6+ species fraction leads to an increased selectivity towards propylene formation while it reduces the selectivity for CO and cracking products. This indicates that Cr 6+ species favor olefin formation over undesired by-products.