Dehydrogenation of ethylbenzene in the presence of CO2over catalysts prepared from hydrotalcite-like precursors

作者：Ye, Xingnan; Ma, Ning; Hua, Weiming; Yue, Yinghong; Miao, Changxi; Xie, Zaiku; Gao, Zi^*

来源：Journal of Molecular Catalysis A: Chemical , 2004, 217(1-2): 103-108.

DOI：10.1016/j.molcata.2004.02.024

• Catalyst system
• Surface areas

Dehydrogenation of ethylbenzene to styrene in the presence of CO 2was investigated over a series of catalysts prepared by calcination of hydrotalcite-like compounds. Mg/Fe mixed oxide catalysts prepared in this way have high specific surface areas and are active for the dehydrogenation reaction. Incorporation of Al3+, Ni2+, Co2+, and Zn2+into the hydrotalcite-like precursors may further enhance the catalytic activity of the calcined catalysts. The Mg/Zn/Al/Fe catalyst affords the highest ethylbenzene conversion of 53.8% and a styrene selectivity of 96.7% at 773 K. The high catalytic activity and stability of the Mg/Zn/Al/Fe catalyst are attributed to the presence of a larger amount of stronger acid sites and a moderate amount of base sites on the catalyst. The temperature-programmed reduction studies show that the reduction of iron oxide species in the catalysts is retarded after incorporation of Zn2+and Al3+. The higher content of iron oxide species in the catalyst system under reaction conditions favors the redox cycle in the reaction and also enhances the dehydrogenation activity.

• 出版日期2004
• 单位复旦大学; 上海交通大学