La2O3 promotional effect to Co3O4/γ-Al2O3 catalyst in the oxidative dehydrogenation of ethylbenzene with CO2 as soft oxidant

Publication date: Available online 23 October 2018Source: Journal of Saudi Chemical SocietyAuthor(s): Venkata Rao Madduluri, Peddinti Nagaiah, Challa Pratap, Paleti Gidyonu, Burri David Raju, Kamaraju Seetha Rama RaoAbstractCo3O4/γ-Al2O3 catalysts with variable Co3O4 loadings (5–20 wt%) and deposition of 15% Co3O4 on La2O3/γ-Al2O3 were prepared by wet impregnation method. La2O3-γ-Al2O3 support with variable composition of La2O3 (2–6 wt%) were prepared by co-precipitation method. All the catalysts were tested for oxidative dehydrogenation of ethylbenzene with CO2 as soft oxidant. Among the Co3O4/γ-Al2O3 catalysts, 15% Co3O4/γ-Al2O3 has shown good performance and hence this catalyst has been chosen to study the effect of La2O3. CO2 pulse chemisorption data indicate more amount of CO2 uptake over 15% Co3O4/4%La2O3/γ-Al2O3 catalyst which clearly indicates that this catalyst exhibits good performance in ethylbenzene dehydrogenation with CO2 as soft oxidant because of reverse water gas shift reaction. Temperature programmed reduction studies indicate that the Co3O4 catalysts follow two step reduction mechanism from Co3O4 to CoO and then to Co and La2O3 promotional effect is visible through easy reduction of Co3O4 species. La2O3 doping has a vital influence in getting enhanced ethylbenzene conversion, styrene yield and alleviates catalyst deactivation compared to that of unpromoted Co3O4/γ-Al2O3 catalyst. TGA studies indicate the presence low amount coke deposition du...

Source: Journal of Saudi Chemical Society - October 23, 2018 Category: Chemistry Source Type: research