Utilization of CO2 and N2 for selective synthesis of styrene from ethylbenzene over high surface area γ-Al2O3 supported molybdenum nitride catalysts

Abstract

The present work highlights the synthesis of styrene from ethylbenzene dehydrogenation by coupling with reverse water gas shift reaction (RWGSR) and ammonia synthesis reactions over high surface area Al2O3 supported molybdenum nitride (γ-Mo2N) catalyst. γ-Mo2N was prepared by in-situ thermal decomposition of molybdenum hexamethylenetetramine complex and the support high surface area Al2O3 (HSA) was prepared by sol-gel method. Different weight loadings of γ-Mo2N (10, 20 and 30) supported on HSA catalysts were systematically characterized by using powder XRD, N2 physisorption, H2 - TPR, XPS and TEM analysis. XRD, TEM and normalized BET surface area analysis reveal highly dispersed nitride species over HSA surface. The synthesized catalysts have been studied for ethylbenzene dehydrogenation reaction using CO2 and N2 as feed gases with different percentage compositions. It was found that CO2 rich N2 feed gas favors higher ethylbenzene conversion due to RWGSR and N2 rich CO2 favors higher selectivity to styrene due to ammonia synthesis. EB dehydrogenation along with RWGSR and ammonia synthesis reactions come along and privileged the formation of higher styrene yields.