The advantage of ceria loading over VSubscript2/SubscriptOSubscript5/Subscript/AlSubscript2/SubscriptOSubscript3/Subscript catalyst for vapor phase oxidative dehydrogenation of ethylbenzene to styrene using COSubscript2/Subscript as a soft oxidant

摘要

The present work highlights the influence of ceria over vanadia/alumina for the oxidative dehydrogenation of ethylbenzene to styrene with CO2 as a soft oxidant. Various weight loadings (0, 3, 5, and 7?%) of ceria were incorporated into 10wt?% V2O5/Al2O3 catalyst by wet impregnation process. Structural and textural characterizations of the catalysts were performed by means of powder X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption of CO2, N2 adsorption–desorption analysis. Over 10?% V2O5/Al2O3, ethylbenzene conversion decreases from 62 to 49?% in a spam of 12?h. Ceria-incorporated catalyst (3?% CeO2/10?% V2O5/Al2O3) showed steady ethylbenzene conversion of nearly 65?% with a styrene selectivity of 96?% for a period of 12?h time. Improved catalytic activity observed on this catalyst can be attributed to the increase in the number of redox/active VOx species after incorporation of ceria. The redox properties of 3?% CeO2/10?% V2O5/Al2O3 and 10wt?% V2O5/Al2O3 were examined by reaction of CO2 in pulses on to the partially reduced catalysts. The spent catalysts were characterized using XRD & TPR analysis to assess the reason for the deactivation of catalysts.