Cs_2O/Al_2O_3-ZrO_2催化剂的制备及催化性能研究

Study on the properties of Cs_2O/Al_2O_3-ZrO_2 catalysts for aldol condensation

本文采用醇盐-凝胶溶胶法制备Al2O3-ZrO2催化剂复合载体,并通过超声浸渍法制备Cs2O/Al2O3-ZrO2催化剂。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱(EDS)等技术考察了复合载体对催化剂的晶相结构、表面形貌的影响;并以甲醛和醋酸甲酯合成丙烯酸甲酯反应为探针,讨论了单一载体及铝锆比不同的复合载体催化剂的催化活性。实验结果表明:经过500℃煅烧的催化剂具有良好的晶形;材料具有蜂窝状孔道,具有良好的通透性;Cs的负载量为4.42%;当mAl2O3∶mZrO2=1∶0.25时,所得催化剂的活性最高,收率达到14.76%。

The alkoxide-sol-gel method was adopted to prepare the Al2O3-ZrO2 composite support.The Cs2O/ Al2O3-ZrO2 catalyst was prepared with the impregnated method,the effect of the crystal structure,surface morphology of the catalysts were examined by the X-ray diffraction（XRD）,scanning electron microscopy（SEM）,energy spectra（EDS）,and etc.And the reaction of formaldehyde and methyl acetate was used as a probe to study the activity of catalyst for both the single support and different Al2O3-ZrO2 composite support.The results showed that the catalyst by calcined at 500℃ has good crystal shape;the materials have honeycomb pores with good permeablity;the values of Cs content are 4.42%.The experiment shows the catalysts’ activty is the best when Al2O3-ZrO2 ratio is 4,and the yield is 14.76%.