包覆型MCM-41和Hβ分子筛负载的Pd催化剂双功能催化性能  

Bifunctional Catalytic Performance of Pd Catalysts Supported on Encapsulated MCM-41 and Hβ Composite Molecular Sieve

作　　者：邹洁[1] 李翔 盛强 尚森森 王伟[1] ZOU Jie;LI Xiang;SHENG Qiang;SHANG Sensen;WANG Wei(College of Chemical and Biology Engineering,Yinchuan University of Energy,Yinchuan 750105;Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-Utilization,College of Chemical Engineering and Materials Science,Tianjin University of Science and Technology,Tianjin 300457,China)

机构地区：[1]银川能源学院化学与生物工程学院,宁夏银川750105 [2]天津科技大学化工与材料学院天津市卤水化工与资源生态化利用重点实验室,天津300457

出　　处：《石油学报(石油加工)》2025年第1期14-21,共8页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(21673029,22108207);宁夏自然科学基金项目(2021AAC03253);重质油国家重点实验室开放基金项目(SKLHOP202202005)资助。

摘　　要：采用水热合成法制备了一种MCM-41分子筛介孔孔道沿Hβ沸石内核向外生长的包覆型MCM-41和Hβ复合分子筛(Mβ)。以PdCl 2的盐酸溶液做浸渍液,用常规等体积浸渍法制备了Pd/Mβ催化剂。另外,还以预先硅烷化的Mβ作载体,以Pd(OAc)_(2)的甲苯溶液作浸渍液,用等体积浸渍法制备了Pd/S-Mβ催化剂。采用X射线衍射、N_(2)物理吸附、透射电镜(TEM)和吡啶吸附红外等手段对催化剂进行了表征,并以十氢萘的开环反应和二苯并噻吩的加氢脱硫反应评价了催化剂的性能,认识了金属中心和酸中心沿颗粒内部径向分布对双功催化剂能性能的影响。TEM结果表明,在Pd/Mβ催化剂中,Pd金属颗粒填充于MCM-41介孔相孔道中;而在Pd/S-Mβ催化剂中,Pd金属颗粒分布于催化剂表面。在十氢萘的开环和二苯并噻吩的加氢脱硫反应中,Pd/Mβ表现出双功能特性,是潜在的性能良好的加氢脱硫催化剂。尽管Pd/Mβ和Pd/S-Mβ酸性质基本一致,但是空间上将表面Pd金属组分与内核Hβ沸石酸组分用不具有酸性的MCM-41介孔相分隔后,会导致Pd/S-Mβ催化剂酸中心不能发挥作用。An encapsulated MCM-41 and Hβ composite molecular sieve(Mβ)with mesopore channels of MCM-41 molecular sieve oriented outward from the inner Hβzeolite core was synthesized by hydrothermal method.A Pd/Mβ catalyst was prepared by the conventional incipient wetness impregnation method using an aqueous hydrochloric acid solution of PdCl 2 as impregnation liquid.Besides,a Pd/S-Mβ catalyst was prepared by the incipient wetness impregnation method when using pre-silylated Mβas carrier and a toluene solution of Pd(OAc)_(2) as impregnation liquid.The catalysts were characterized by X-ray diffraction,N_(2) physisorption,transmission electron microscopy(TEM),and pyridine adsorption Fourier-transform infrared(Py-IR).Moreover,the catalytic performances of Pd catalysts were evaluated by the ring-opening reaction of decalin and the hydrodesulfurization of dibenzothiophene,so as to gain an insight into the effect of intragranular distribution of metal and acid sites along the radial direction on the performance of bifunctional catalysts.The TEM results demonstrates that in the Pd/Mβcatalyst,Pd particles are filled in the mesopores of the MCM-41 phase;while in the Pd/S-Mβ catalyst,Pd particles are distributed on the external surface of the catalyst.In the ring-opening reaction of decalin and the hydrodesulfurization of dibenzothiophene,Pd/Mβ acts as a normal bifunctional catalyst,and is a promising hydrodesulfurization catalyst with good performance.Although Pd/S-Mβ and Pd/Mβ possess nearly identical acidity,the spatial separation of surface Pd particles and acid sites by non-acidic MCM-41 phase in Pd/S-Mβ will lead to almost complete loss of acid function.

关 键 词：颗粒内分布 钯 双功能催化剂 HΒ沸石 MCM-41分子筛 包覆型分子筛 复合分子筛 

分 类 号：TE624.9[石油与天然气工程—油气加工工程]