A sustainable synthesis of a monometallic vanadium-supported H-beta zeolite catalyst for CO2-assisted oxidative dehydrogenation of butane to olefins

Abstract

Developing methods to utilize CO₂ emissions is crucial for long-term environmental sustainability, as underground storage will eventually become impractical. One promising approach is the development of active catalysts for the CO₂-assisted oxidative dehydrogenation of butane (CO₂ ODHB) to olefins. This study presents the results of the performance of different vanadium loadings supported on H-beta Zeolite synthesized using the solvent-free approach for the CO₂ ODHB. The catalysts were synthesized and characterized regarding surface morphology, surface reducibility, acidity, and textural properties using XRD, SEM-EDX, H₂-TPR, NH₃-TPD, and BET analysis. The H₂-TPR result showed that the 10 wt%V/H-beta zeolite displayed higher reducibility and stronger metal-support interaction. The BET surface area increases with the percentage of vanadium oxide, except for the 5 % vanadium oxide content. The NH₃ -TPD profile showed that as the loading of vanadium oxide increases on the surface of the zeolite support, the surface acidity of the catalyst increases from 2.5 wt%V/H-beta Zeolite to 10 wt%V/H-beta Zeolite and then drops at 15 wt%V/H-beta Zeolite. During a 10-hour time-on-stream test, the catalyst maintained stable butane conversion and C₄ olefin selectivity of approximately 31 % and 62 %, respectively, at 600 °C using a 10 wt%V/H-beta Zeolite catalyst. In-situ DRIFT measurements provided insights into the dynamic changes on the catalyst surface and the evolution of reaction intermediates during the CO₂-assisted oxidative dehydrogenation of butane. The synthetic approach demonstrated a promising strategy for synthesizing an eco-friendly catalyst effective for CO₂-assisted oxidative dehydrogenation of butane to olefins.