制备方法对Zr-Fe基乙苯脱氢催化剂性能的影响

分别采用浸渍法、溶胶-凝胶法、水热合成法和共沉淀法制备了Al2O3负载的Zr-Fe基催化剂25 Zr 5 Fe/Al2O3，相应标记为25 Zr 5 Fe/Al2O3-imp，25 Zr 5 Fe/Al2O3-sol-gel， 25 Zr 5 Fe/Al2O3-ht和25 Zr 5 Fe/Al2O3-cop；对其进行了XRD，BET，H2-TPR，NH3-TPD表征，考察了其晶相组成、孔结构、氧化还原性、酸性等性质；将制备的这4种基催化剂用于乙苯脱氢反应中，结合乙苯脱氢活性，简要分析了其构效关系。结果表明:这4种25 Zr 5 Fe/Al2O3催化剂的乙苯脱氢催化初始活性顺序与其所含有的中强酸含量高低顺序一致，即从大到小依次为25 Zr 5 Fe/Al2O3-imp，25 Zr 5 Fe/Al2O3-sol-gel，25 Zr 5 Fe/Al2O3-cop，25 Zr 5 Fe/Al2O3-ht；25 Zr 5 Fe/Al2O3催化剂的催化活性、稳定性和选择性，不仅与其相应表面的酸类型有关，而且受其孔结构的影响也比较大。

Influence of preparation method on performance of Zr-Fe-based ethylbenzene dehydrogenation catalyst

The Zr-Fe-based catalysts（25 Zr 5 Fe/Al2O3） using Al2O3 as the carrier were prepared by impregnation method， sol-gel method， hydrothermal synthesis method and co-precipitation method and were labeled as 25 Zr 5 Fe/Al2O3-imp，25 Zr 5 Fe/Al2O3-sol-gel， 25 Zr 5 Fe/Al2O3-ht and 25 Zr 5 Fe/Al2O3-cop， respectively. Then， such catalysts were characterized by XRD， BET， H2-TPR and NH3-TPD to investigate their crystal phase composition， pore structure， redox， acidity， etc. Such 4 kinds of 25 Zr 5 Fe/Al2O3 catalysts were used for the ethylbenzene dehydrogenation reaction. Combined with the dehydrogenation activity of ethylbenzene， the structure-activity relationship were briefly analyzed. The results showed that the initial activity ranking of the above4 catalysts for ethylbenzene dehydrogenation was consistent with the ranking of their corresponding medium and strong acid contents， and the order from large to small was as followed:25 Zr 5 Fe/Al2O3-imp， 25 Zr 5 Fe/Al2O3-sol-gel， 25 Zr 5 Fe/Al2O3-cop， 25 Zr 5 Fe/Al2O3-ht. The catalytic activity of 25 Zr 5 Fe/Al2O3 catalysts were not only related to the acid types of their corresponding surfaces， but also greatly affected by their pore structures.