钨含量对W/SiO_2/Al_2O_3催化剂上1-丁烯自歧化反应的影响（英文）  

Influence of Tungsten Loadings on the 1-Butene Metathesis Reaction over W/SiO_2/Al_2O_3 Catalysts

作　　者：柳娜[1] 张辉[1] 薛念华[2] 丁维平[2] 

机构地区：[1]西安科技大学化学与化工学院,西安710054 [2]南京大学化学与化工学院,介观化学教育部重点实验室,南京210093

出　　处：《物理化学学报》2015年第5期933-940,共8页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(21403164);National Innovation Experiment Program for University Students,China(S14024)~~

摘　　要：采用浸渍法制备了一系列钨负载量不同的W/Si O2/Al2O3催化剂.采用X射线衍射(XRD)、激光拉曼(Raman)光谱、紫外-可见(UV-Vis)光谱、氢气程序升温还原(H2-TPR)和氨程序升温脱附(NH3-TPD)等技术对催化剂进行了表征.实验结果表明:钨的负载量对催化剂上氧化钨物种的分散程度、还原性以及催化剂的酸性有非常重要的影响.对该类催化剂上1-丁烯自歧化反应进行了详细考察,结果表明:当钨的质量分数为6.0%时,W/Si O2/Al2O3催化剂表现出最佳的歧化活性和稳定性.原因在于6.0%的钨负载量可以使催化剂上氧化钨物种具有中等程度的分散性、合适的还原性,并且使催化剂具有一定程度的酸性,这些因素有利于在催化剂上形成烯烃歧化活性位.A series of W/Si O2/Al2O3 catalysts with various tungsten loadings were synthesized via the impregnation method. The as-synthesized catalysts were characterized by X-ray diffraction（XRD）, Raman spectroscopy, ultraviolet-visible（UV-Vis） spectroscopy, H2temperature-programmed reduction（H2-TPR）, and NH3temperature-programmed desorption（NH3-TPD）. The results reveal that the tungsten loadings were crucial to the dispersion and reducibility of the tungsten oxide species and the acidity of catalysts. The catalytic performances were also investigated during the metathesis of 1-butene to propene. Amongst these catalysts,W/Si O2/Al2O3 with a tungsten mass fraction of 6.0% gave the highest activity and stability during the 1-butene metathesis reaction. The excellent catalytic performance of the catalyst containing a tungsten mass fraction of 6.0% is attributed to its moderate dispersion, suitable reducibility of the WOxspecies and suitable acidity. We speculate that these factors are favorable for the formation of active centers for olefin metathesis.

关 键 词：1-丁烯 丙烯 歧化 钨负载量 催化活性 

分 类 号：O643.32[理学—物理化学]