CrMn‐based catalysts for oxidative dehydrogenation of propane to propylene with CO₂

Abstract

The paper investigates the catalytic oxidative dehydrogenation of propane with carbon dioxide (ODH‐CO2) as a promising route for propylene production, an avenue yet to be commercially developed. Utilizing the incipient wetness catalyst preparation method, CrMn catalysts were synthesized on three supports (γ‐Al2O3, ZSM‐5, and SBA‐15). Comprehensive characterization through Brunauer–Emmett–Teller (BET) analysis, X‐ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM)/scanning transmission electron microscopy (STEM)‐energy‐dispersive X‐ray spectroscopy (EDS), and hydrogen temperature programmed reduction (H2‐TPR) was conducted to comprehend catalyst behaviour. Among the six catalysts tested, Cr/SBA‐15 was exhibited as the best performer, achieving propane and CO2 conversions of 36.2% and 14.1%, respectively, with a propylene selectivity of 33.4%. Over a 50‐h time on stream (TOS), it demonstrated gradual declines in conversions while retaining 75% of initial values. The incorporation of manganese as a promoter effectively mitigated coke formation, albeit with slight reductions in propane conversion and propylene selectivity.