Fe-Al-P-O催化1,2-二氯丙烷与水环氧化制环氧丙烷反应机理  

Mechanism of Epoxidation of 1,2-Dichloropropane with Water to Produce Propylene Oxide Catalyzed by Fe-Al-P-O

作　　者：赵春[1] 顾修君[1] 钟顺和[1] 肖秀芬[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《催化学报》2005年第8期677-682,共6页

基　　金：辽宁省科委基金资助项目.

摘　　要：采用溶胶凝胶法制备了非晶态FeAlPO催化剂,并用IR,XRD,TEM,N2吸附及微反等技术对其组成、结构特性以及催化性能进行了表征和评价,通过IR和TPDMS等技术着重研究了其化学吸附性能,探讨了表面催化反应的机理.结果表明,FeAlPO催化剂是FePO4和AlPO4均匀混合形成的非晶态混合物,能够促进1,2二氯丙烷和水反应高选择性地生成环氧丙烷,其Lewis酸位的Fe3+和Lewis碱位P=O的O2-是催化剂表面的主要活性位,能使水进行解离吸附并形成Fe-O-和P-OH键.1,2二氯丙烷通过Cl-与P-OH键中的H+作用形成桥式吸附态是反应进行的关键.Abstract： The non-crystal Fe-Al-P-O catalyst was prepared by the sol-gel method and used to synthesize propylene oxide （PO） from 1,2-dichloropropane （DCP） and H2O. The catalyst composition, structure and catalytic behavior were characterized and evaluated by infrared spectroscopy （IR）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, N2 adsorption and microreactor. The reaction mechanism was studied by chemisorption-IR and temperature-programmed desorption-mass spectroscopy （TPD-MS）. The results show that the Fe-Al-P-O catalyst is a non-crystal mixture of FePO4 and AlPO4 and can effectively promote the aim reaction with high selectivity for PO. Lewis acid sites Fe^3＋ and Lewis base sites O^2- in P=O bonds are the main active sites on the catalyst surface, on which H2O can be chemisorbed and dissociated to form P-OH and Fe-O^- species. Through the interaction of Cl^- and P-OH, DCP can be chemisorbed to form a bridge chemisorption state, which is the key step in the reaction. Propylene adsorbed on O^- of the Fe-O^- bond is a useful intermediate for the PO production.

关 键 词：铁 铝 复合磷酸盐 1 2-二氯丙烷 环氧化 环氧丙烷 

分 类 号：O621.25[理学—有机化学]