Synthesis, Characterization, and Evaluation of Mesoporous MCM-41-supported Molybdenum Hydrotreating Catalysts

Mesoporous MCM-41 material with high surface area and narrow pore size distribution was synthesized and used as a support for Mo, CoMo, and NiMo catalysts. The molybdenum loading was varied from 2-14 wt% on MCM-41. On 10 wt% Mo/MCM-41, the promoter Co or Ni concentration was varied from 1-5 wt%. All the catalyst samples were characterized by surface area, low temperature oxygen chemisorption, x-ray diffraction (XRD), and temperature programmed reduction methods. Characterization results show that Mo is well dispersed on MCM-41 up to 10 wt%. The catalytic activities were evaluated for thiophene hydrodesulphurization (HDS), cyclohexene hydrogenation (HYD), and furan hydrodeoxygenation (HDO). All three catalytic functionalities vary in a similar manner to that of oxygen chemisorption as a function of Mo loading, indicating that there is a correlation between oxygen uptake and catalytic sites. The activities of these catalysts were compared with γ-Al₂O₃- and amorphous SiO₂-supported catalysts. It was found that MCM-41-supported Mo catalysts displayed superior activities.     

ZSM-5/MCM-41介孔硅铝分子筛担载Pd和Pt制备加氢脱硫催化剂

将ZSM-5溶于偏硅酸钠水溶液,以十六烷基三甲基溴化铵作模板剂,用水热合成法自组装合成了具有较强酸性和不同SiO₂/Al₂O₃摩尔比(n(SiO₂)/n(Al₂O₃))的ZSM-5/MCM-41介孔硅铝分子筛（记为ZM(x),x=n(SiO₂)/n(Al₂O₃)）。以二苯并噻吩（DBT）质量分数为0.8%的十氢萘溶液为模型化合物,考察了Si-MCM-41和ZM(x)担载的Pd和Pt催化剂催化加氢脱硫（HDS）反应的活性。结果表明,担载Pt和Pd不会破坏ZM(x)的介孔结构;DBT在Pd催化剂上主要通过加氢路径脱硫,而在Pt催化剂上则直接脱硫和加氢2条反应路径并重;Si-MCM-41为载体的催化剂HDS活性较低并且失活较快,以ZM(x)为载体的Pd和Pt催化剂加氢活性、加氢脱硫活性、加氢裂化活性及稳定性都有显著提高;ZM(x)担载的Pt和Pd催化剂催化HDS反应的活性可能与其活性组分分散度以及载体的B酸和L酸比例（B/L）有关,具有较好的活性组分分散度和较高B/L比例的ZM(60)担载的Pd和Pt催化剂表现出最佳的加氢脱硫活性和稳定性。     

厚壁MCM-41中孔分子筛的合成

在水热条件下,以硅酸钠、活性氧化铝为硅源和铝源,表面活性剂ＣＴＭＡＢ为结构模板剂,对合成过程的凝胶组成、晶化温度、晶化时间等因素进行正交试验,成功地合成出相对结晶度高的厚壁ＭＣＭ－４１中孔分子筛材料。采用ＸＲＤ、低温Ｎ２吸附（ＢＥＴ）等测试手段对合成的ＭＣＭ－４１样品进行表征。考察了影响ＭＣＭ－４１孔壁厚度的主要因素。结果表明,向体系中加入适量的稀硫酸和有机酸,有效地控制了体系的ｐＨ,提高了ＭＣＭ－４１的相对结晶度和孔壁厚度。通过优化合成条件,合成出孔径３１８ｎｍ、比表面大于１０００ｍ２·ｇ－１、孔壁厚度２８２ｎｍ的ＭＣＭ－４１中孔分子筛。     

MCM-41中孔分子筛研究进展

综述了MCM-41中孔分子筛的合成方法、形成机理，从应用的角度分析探讨了分子筛改性研究，重点介绍了中孔分子筛增大孔径的几种方法。概述了MCM-41中孔分子筛在石油化工领域的应用发展情况，并对应用前景进行了分析。     

One-Pot Synthesis of Hybrid Materials Composed by Crystalline ZSM-5 and Noncrystalline MCM-41 Phases

A synthesis route for obtaining combinations of ZSM-5/MCM-41 materials led to the growth of zeolitic crystallites embedded into the mass of MCM-41 mesoporous materials, which have distinct textural properties, surface areas of about one half of conventional MCM-41, and the formation of double wall thickness. These data were determined from X-ray diffraction and N₂-adsorption data.     

含钴 WP/MCM-41催化剂二苯并噻吩氢脱硫性能

 制备了不同 Co 含量的 WP/MCM-41催化剂,并采用X-射线衍射(XRD)、BET 比表面积以及 X-光电子能谱(XPS)等分析手段对催化剂进行了表征,采用微反装置对该催化剂二苯并噻吩(DBT)加氢脱硫(HDS)性能进行了评价。结果表明,WP 是催化剂的主要活性相,Co 的加入不同程度地促进了 WP 晶相生长,同时在催化剂表面形成了具有一定活性的类似 Co—W—P 结构的双金属磷化物。Co 对 WP/MCM-41催化剂的 DBT HDS 反应有促进作用,催化剂中活性位数量以及主要活性相 WP 在催化剂表面所占比例是决定催化剂活性的主要因素。其中,Co 质量分数为9%的催化剂（Cat-Co-9）具有相对最高 DBT HDS 活性,其 DBT 脱硫率和转化率分别为63.7%和60.4%,比未加 Co 的催化剂分别提高13.2%和13.7%。DBT 在 WP/MCM-41催化剂上以加氢脱硫(HYD)路径为主,Co 的加入对 HYD 路径起到促进作用,但随着 Co 加入量的提高,其 HYD 路径产物选择性逐渐降低,而直接脱硫(DDS)路径产物选择性不断提高。     

Synthesis and characterization of MCM-41-supported nano zirconia catalysts

Series of MCM-41 supported sulfated Zirconia (SZ) catalysts with different loadings (2.5–7.5% wt.) were prepared using direct impregnation method. The acquired solid catalysts were characterized structurally and chemically using X-RD, HRTEM, BET, FT-IR, Raman spectroscopy and TPD analysis. The acidity of the solid catalysts was investigated through cumene cracking and isopropanol dehydration at different temperatures. As the SZ loading increases, the surface acidity of the mesoporous catalysts was enhanced, this was reflected by the higher catalytic activity toward cumene cracking and isopropanol dehydration.     

MCM-41沸石分子筛的微波合成与表征

以溴代十六烷基吡啶（ＣＰＢｒ）为模板剂,硅溶胶为硅源,用微波辐射的方法合成高结晶度的ＭＣＭ ４１中孔分子筛。探讨了微波晶化时间、微波反应釜压力等合成影响因素,确定了合适的配比范围及合成条件。利用ＸＲＤ、ＴＥＭ等方法对ＭＣＭ ４１中孔分子筛的物相和晶貌作了表征。     

有机蒙脱土与MCM-41介孔分子筛的共同填加对聚丙烯基复合材料性能的影响

以纳米有机蒙脱土(OMMT)、MCM-41纳米介孔分子筛(不含模板剂)、OMMT/MCM-41混合物(m(OMMT):m(MCM-41)=1:1)为填料(增强组分),通过双螺杆挤出机制备了聚丙烯(PP)基纳米复合材料;考察了填料种类及添加量对纳米复合材料性能的影响。实验结果表明,以OMMT/MCM-41混合物为填料时,两种粒子起到了协同增强、增韧的作用;当OMMT/MCM-41混合物的添加量(以体系的总质量计)为2.0%时,PP基纳米复合材料的拉伸强度和冲击强度达到最大值,分别为45.1MPa和38.6kJ/m2,比PP分别提高了30%和53%;同时添加OMMT和MCM-41的PP基纳米复合材料的热稳定性高于单独填加OMMT或MCM-41的PP基纳米复合材料。     

Hydrogenation of Naphthalene on HY/MCM-41 Composite Supported Sulfided Ni-Mo Catalysts

A series of mesoporous molecular sieves, MCM-41 with different Si/Al molar ratios, were synthesized by hydrothermal method. The influence of aluminum content on the properties and pore structure of MCM-41 molecular sieves was investigated. The supported Ni-Mo catalysts with MCM-41 and γ-Al₂O₃ as supports were synthesized by impregnating with Ni-Mo-P solution. The activity of the catalysts was characterized by hydrogenation of naphthalene. The influence of Si/Al ratio of MCM-41 on hydrogenation activity of the catalysts was investigated. The results indicated that the relative crystallinity of MCM-41 decreases with the increase of aluminum content in the molecular sieves; however, the hydrogenation activity of the catalysts, especially the ring-opening activity, increases with the increase of aluminum content. The synergistic effect for hydrogenation of naphthalene was found by mixing MCM-41 and HY molecular sieves. At 360°C the catalysts with HY and MCM-41 mixture as supports had higher activity. The reaction network for hydrogenation of naphthalene includes two parallel pathways; naphthalene was hydrogenated to tetralin, then the isomerization and ring-opening of tetralin occurred, or tetralin was further hydrogenated to decalin, followed by the isomerization and ring-opening of decalin.     

MCM-41介孔分子筛负载取代酞菁钴催化氧化乙硫醇

采用浸渍法将β-四(4-羧基苯氧基)酞菁钴((p-HOOCPhO)4PcCo)负载在MCM-41介孔分子筛中制备了(p-HOOCPhO)4PcCo/MCM-41催化剂,通过X射线衍射、紫外-可见漫反射光谱、Raman光谱、N2吸附方法对催化剂的结构和组成进行了表征,研究了常温、常压下,该催化剂催化氧化乙硫醇反应的动力学。实验结果表明,MCM-41介孔分子筛是(p-HOOCPhO)4PcCo的良好载体,(p-HOOCPhO)4PcCo在MCM-41介孔分子筛中不易聚集,主要以单体形式存在。(p-HOOCPhO)4PcCo/MCM-41催化剂具有优良的催化氧化乙硫醇反应的性能,且具有酶催化氧化反应的特征,遵循米氏方程动力学规律,最大反应速率和米氏常数分别为1.94mL/min和0.018mol/L。     

介孔分子筛MCM-41的合成及其催化噻吩与异丁烯烷基化反应性能

采用水热合成法制得不同硅铝比的介孔分子筛MCM - 41 ,并通过XRD ,BET ,NH3 -TPD方法对催化剂进行了表征 ,结果表明 ,弱酸性介孔分子筛HMCM - 41具有较高的相对结晶度、较大的比表面积、孔径和酸量。同时 ,不同焙烧方式对催化剂相对结晶度及比表面积影响较大 ,N2 气氛焙烧有利于保护介孔分子筛MCM - 41的骨架完整 ,提高其相对结晶度。以噻吩为模型化合物 ,异丁烯为烷基化剂 ,对HMCM - 41分子筛催化噻吩与异丁烯的烷基化反应性能进行了考察。在反应温度 80℃、常压、进料气体 (异丁烯 /N2 摩尔比为 1 /1 )流量 5ml/min、WHSV =2 33h- 1的条件下 ,噻吩转化率高达 95%以上     

ZSM-5/MCM-41微-介孔复合分子筛的微波合成及表征

以碱液处理的ZSM-5分子筛反应液为硅铝源、十六烷基三甲基溴化铵为介孔模板剂,通过微波法快速合成了具有微-介孔结构的ZSM-5/MCM-41复合分子筛。考察了反应时间、反应温度和体系p H对合成产物的影响,优化了合成条件,并利用XRD、SEM、TEM、N2吸附-脱附等手段对合成产物进行了表征。实验结果表明,反应温度为120℃时,在0.5 mol/L的Na OH溶液中,利用微波消解ZSM-5分子筛原粉30 min后,调节体系p H为10.5,继续晶化30 min,可得到ZSM-5/MCM-41复合分子筛。相比于传统水热法,微波法的合成效率提高了20倍以上。所得ZSM-5/MCM-41复合分子筛中既保留了ZSM-5分子筛的微孔结构,也形成了典型的MCM-41分子筛的介孔结构,且所得ZSM-5/MCM-41复合分子筛的孔体积、比表面积较ZSM-5分子筛提高了近3倍。     

H_6P_2W_(18)O_(62)/MCM-41催化剂的制备、表征及其催化合成乙酰水杨酸

采用浸渍法将Dawson结构的磷钨酸H6P2W18O62(简写为P2W18)负载在MCM-41分子筛上,制备出新型P2W18/MCM-41催化剂;采用FTIR,XRD,SEM,EDS等方法对催化剂进行了表征。表征结果显示,P2W18/MCM-41催化剂既保持了MCM-41分子筛的孔道结构,又保持了P2W18的Dawson结构。同时研究了P2W18/MCM-41催化剂对乙酰水杨酸合成反应的活性,通过正交实验确定了优化工艺条件:n(水杨酸)∶n(乙酸酐)=1.0∶1.5、P2W18/MCM-41催化剂用量2.7%(基于反应物的质量)、反应温度80℃、反应时间10 min。在此优化条件下,乙酰水杨酸收率为88.1%。P2W18/MCM-41催化剂重复使用5次,乙酰水杨酸收率仍可达76.7%。     

Ru/MCM-41催化剂表面的Ru物种

采用等体积浸渍法制备了用于苯选择加氢制环己烯的Ru/MCM-41催化剂,对其进行了X射线衍射、透射电镜、程序升温还原和原位漫反射红外光谱等手段表征,以确定MCM-41表面Ru物种的存在状态.结果发现,Ru物种颗粒均匀地分散在MCM-41孔道内,平均粒径为2.1 nm.在MCM-41表面存在Ru0、RuOx、RuClO和RuCl3等Ru物种;并且随着助剂Zn的加入,RuOx、RuClO等物种变得不稳定,而对于Ru0的影响较小.Ru0的加氢活性较强,易于使苯发生深度加氢得到环己烷;而RuOx、RuClO的加氢活性较弱,更易得到环己烯.Zn的加入使Ru/MCM-41催化苯选择加氢制环己烯的活性和选择性同时下降.     

Catalytic cracking of isopropylbenzene over hybrid HZSM-12/M41S (M41S = MCM-41 or MCM-48) micro-mesoporous materials

The catalytic cracking of isopropylbenzene was investigaded over hybrid ZSM-12/MCM-41 and HZSM-12/MCM-48 micro-mesoporous materials, in order to verify the effect of the acid site of the accessibility of mesoporous channels combined with the acid sites into the zeolite. The hybrid materials were synthesized by the hydrothermal method using the template mechanism. The obtained materials were characterized by X-ray diffraction and BET isotherms using nitrogen adsorption-desorption at 77 K. The X-ray diffraction patterns presented characteristic peaks of the microporous and mesoporous phases. These analysis revealed the formation of ordered hexagonal MCM-41 or cubic MCM-48 mesoporous phases, associated with the ZSM-12 structure. In order to generate acid sites, the materials were ion exchanged with ammonium chloride solution. The calcined hybrid materials were tested as catalyst for cracking of isopropyl-benzene, using a fixed bed reactor at 450 ^oC and nitrogen gas. The catalytic tests showed that the HZSM-12/AlMCM-41 and HZSM-12/MCM-48 hybrid materials have potential for use in cracking reactions, bening more active than the zeolite or the M41S alone. The catalytic activities of the hybrid materials can be associated with a synergistic effect between the acid sites present on the zeolitic phase and the mesoporous phase. In order to verify how the structure of the hybrid materials may affect and control their catalytic performances, the results were compared with HZSM-12 physically mixed with MCM-41 and MCM-48.     

MCM-41和氧化锆负载铂-磷钨酸双功能催化剂的正戊烷临氢异构化性能

分别以MCM-41分子筛和氧化锆为载体,采用共浸渍法制备了负载Pt和磷钨酸的金属-酸性位双功能催化剂,在常压、临氢条件下研究了两种不同载体负载的催化剂对正戊烷异构化反应的催化性能;采用XRD,FTIR,XPS,NH_3-TPD等手段对试样进行了表征。表征结果显示,以氧化锆为载体的催化剂中载体与活性组分之间存在明显的相互作用,而以MCM-41分子筛为载体的催化剂中则未明显表现出载体和活性组分之间的相互作用;与以MCM-41分子筛为载体的催化剂相比,以氧化锆为载体的催化剂保持了较强的酸强度,且催化剂中的Pt元素具有更好的还原度。实验结果表明,以氧化锆为载体的催化剂在较低贵金属和磷钨酸负载量的条件下表现出更高的异构化催化性能,这可能归因于氧化锆和活性组分之间存在的相互作用、催化剂中金属组分更易被还原以及具有更高的酸强度。     

MCM-41/Y介孔-微孔复合分子筛的合成及其加氢裂化性能研究

以Y分子筛、水玻璃和硫酸铝为原料,采用二元混合表面活性剂,水热晶化合成了MCM-41/Y介孔-微孔复合分子筛,并用XRD,SEM,TEM,N2吸附-脱附和Py-IR等多种分析手段对其进行了分析表征。同时以MCM-41/Y复合分子筛和无定形硅铝为酸性组分,以W-Ni为活性金属组分,制备了加氢裂化催化剂MYC,并在200 mL加氢评价装置上进行了加氢性能评价。结果表明,MCM-41/Y复合分子筛中存在着复合的MCM-41六方介孔相和Y微孔相;加氢裂化催化剂MYC催化活性较好,在反应压力15 MPa、氢油体积比1 500∶1、体积空速1.5 h-1的条件下,中油选择性为74.82%,C5+液体收率为98.56%,65～165℃重石脑油的芳潜为43.6%,165～370℃柴油的十六烷值为62.2,大于370℃尾油BMCI值为7.1,分别可作为优质的重整装置进料、柴油调合组分及乙烯裂解原料。     

阴阳离子表面活性剂混合模板剂合成介孔MCM-48分子筛

采用溶胶-凝胶法,以阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和阴离子表面活性剂十二烷基硫酸钠(SDS)混合体系为模板剂,在较大幅度降低模板剂用量(模板剂与硅源的摩尔比从0.55降至0.177)的条件下,合成了高度有序的介孔MCM-48分子筛。为提高分子筛合成的重复性,对影响介孔MCM-48分子筛合成的因素,如水与硅的摩尔比(简称水硅比)、晶化时间及混合模板剂中SDS与CTAB的摩尔比进行了考察。实验结果表明,最佳合成配方中水硅比为62,反应条件为373 K下晶化72 h,混合模板剂中SDS与CTAB的摩尔比为0.164;在此条件下合成的介孔MCM-48分子筛的孔径为2.72 nm,比表面积为861.8 m2/g。