Effects of Al doping on CeZr solid solution for oxidative dehydrogenation of ethylbenzene with CO 2

For improving the oxygen storage/release capacity of ceria-zirconia solid solution, Ce 0.5 Zr 0.5 O 2 -Al 2 O 3 mixed oxides were prepared by a co-precipitation method and applied in the oxidative dehydrogenation of ethylbenzene to styrene with carbon dioxide. Ce 0.5 Zr 0.5 O 2 -Al 2 O 3 mixed oxides were characterized by powder X-ray diffraction, Raman spectroscopy, N 2 -sorption, H 2 temperature-programmed reduction, and X-ray photoelectron spectroscopy. Results show that Al 2 O 3 acts as a diffusion barrier. The addition of Al prevents the growth of Ce 0.5 Zr 0.5 O 2 crystallite size, increases the specific surface area and oxygen storage capacity of Ce 0.5 Zr 0.5 O 2 -Al 2 O 3 mixed oxides. The specific surface area and oxygen storage capacity of Ce 0.5 Zr 0.5 O 2 -Al 2 O 3 mixed oxides are 51.8 m 2 /g higher and 69.4 μmol/g more than those of Ce 0.5 Zr 0.5 O 2 mixed oxides. The ethylbenzene conversion over Ce 0.5 Zr 0.5 O 2 -Al 2 O 3 mixed oxides is about 10% higher than that over Ce 0.5 Zr 0.5 O 2 mixed oxides after 5 h reaction.