The advantage of ceria loading over V2O5/Al2O3 catalyst for vapor phase oxidative dehydrogenation of ethylbenzene to styrene using CO2 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 VO_x species after incorporation of ceria.