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。     

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

Abstract

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.     

hysicochemical Properties and Catalytic Performance of a Novel Aluminosilicate Composite Zeolite for Hydrocarbon Cracking Reaction

A novel micro-micro/mesoporous aluminosilicate ZSM-5-Y/MCM-41 composite molecular sieve with a MCM-41 type structure was synthesized through a novel process of the self-assembly of CTAB surfactant micellae with silica-alumina source originated from alkaline treatment of ZSM-5 zeolite. The physical properties of the ZSM-5-Y/MCM-41 composite molecular sieve were characterized by XRD, Py-FTIR and N2 adsorption-desorption techniques. Different kinds of molecular sieves including ZSM-5, Y zeolite, Al-MCM-41, ZSM-5/MCM-41 and ZSM-5-Y/MCM-41 as cracking catalysts were investigated, using 1,3,5-triisopropylbenzene (1,3,5-TIPB) as the probe molecule. Catalytic tests showed that the ZSM-5-Y/MCM-41 composite molecular sieve exhibited higher catalytic activity compared with the microporous ZSM-5 zeolite, Y zeolite, mesoporous Al-MCM-41 molecular sieve and ZSM-5/MCM-41 composite molecular sieve under the same conditions. The remarkable catalytic activity was mainly attributed to the presence of the hierarchical pore structure and proper acidity in the ZSM-5-Y/MCM-41 composite catalyst. Meanwhile, a carbenium ion mechanism was put forward for the cracking of 1,3,5-TIPB.     

Investigation of ZSM-5/MCM-41 Composite Molecular Sieve for Reducing Olefin Content of FCC Gasoline

ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N2 adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were analyzed.Using FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3 h-1,and a reaction pressure of 2.0 MPa.The results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM-41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization activity.With a largest olefin-reducing capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.     

Cu(phen)_2L/MCM-41(L=丁二酸)催化环己烷合成环己酮的研究

采用水热合成法合成了分子筛MCM-41,以γ-氨丙基三乙氧基硅烷将其表面官能化,将合成的金属配合物固载于官能化的分子筛MCM-41之中制得负载型催化剂。XRD、BET、FT-IR等表征结果表明,配合物被固载于分子筛后,其结构仍保持完整。以双氧水氧化环己烷制备环己酮为特征反应,考察了负载催化材料的催化性能。结果表明该催化剂具有较高的活性,最佳反应条件为:乙腈为溶剂,反应时间10h～12h,反应温度在70℃～90℃,此时,环己烷的转化率达到33.7%,环己酮的选择性达85.3%。     

含锡MCM—41型分子筛的合成与表征

采用水热晶化法首次合成出具有ＭＣＭ－４１型结构的中孔杂原子ＳｎＭＣＭ－４１分子筛，ＸＲＤ、骨架ＩＲ，紫外漫反射，固体魔角核磁等测试结果表明，锡原子处于分子筛骨架上。苯酚羟基化反应显示，ＳｎＭＣＭ－４１具有一定的选择催化氧化性能。     

MCM-41作载体制备磷化钼加氢脱硫催化剂

通过原位还原方法制备了MCM-41担载的MoP催化剂并用TPR和XRD方法对其进行了表征。选用二苯并噻吩(DBT)作模型化合物,考察了催化剂的加氢脱硫(HDS)反应活性和产物分布。结果表明,MoP/MCM-41催化剂的HDS反应活性明显高于MoP/Al2O3催化剂,从加氢脱硫产物分布看,DBT在MoP/Al2O3催化剂上主要通过直接脱硫路径脱硫,而在MoP/MCM-41催化剂上,直接脱硫和预加氢脱硫路径都发挥了重要作用。由中性和碱性浸渍液制备催化剂的HDS活性相当,高于用酸性浸渍液制备的催化剂。     

微波法合成含磷MCM-41分子筛及催化性能研究

采用微波法合成了含磷MCM-41分子筛。运用XRD、SEM、NH3-TPD、BET、NMR手段对合成的分子筛进行表征。结果表明,该分子筛主要有弱酸和中强酸中心,无强酸中心,酸量为0.349 ~0.553 mmol/g;磷原子已经成功进入了分子筛的骨架结构。分别选用1,3,5-三异丙基苯和正十四烷作为反应物,使用自动微反装置,对分子筛进行催化活性的评价。结果表明,采用含磷MCM-41分子筛为催化剂,1,3,5-三异丙基苯的转化率为87.1%,正十四烷的转化率为56.2%,均高于MCM-41分子筛为催化剂时的转化率。     

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。     

分子筛负载ZrOCl2催化剂对2-甲基吲哚与环己烯酮-2 Michael加成的催化性能

采用浸渍法制备了ZrOCl2/分子筛催化剂,并对其进行XRD、SEM、BET等表征。在无溶剂条件下,考察了其催化2-甲基吲哚与环己烯酮-2的Michael加成反应合成药物中间体3-(2-甲基-1H-吲哚-3-基)环己酮的催化性能。结果表明,分子筛比表面积对催化剂活性影响较大,而分子筛酸性的协同催化效应并不明显,ZrOCl2/H-BEA、ZrOCl2/H-ZSM-5、ZrOCl2/H-MCM-41和ZrOCl2/H-USY 4种催化剂中ZrOCl2/H-MCM-41表现出较高的催化活性。以30%ZrOCl2/H-MCM-41为催化剂,在环己烯酮-2与2-甲基吲哚的摩尔比1.1、催化剂用量7.5%、反应温度80℃、反应时间60min的条件下,3-(2-甲基-1H-吲哚-3-基)环己酮的产率达到97.5%。     

丙烯和苯液相烷基化反应中分子筛性能的研究

对丙烯和苯液相烷基化反应中的几种分子筛的性能进行了比较研究。结果表明,MCM-56分子筛催化剂烷基化反应稳定性及产物选择性明显优于Y、β分子筛催化剂。MCM-56分子筛催化剂更能适应低温反应和低苯烃比反应,推荐工艺条件为:温度130～145℃、压力2 5MPa、n(苯)/n(烃)=2～3、丙烯空速0 8～1 0h-1。     

氯化铜在MCM-41中的组装及其在萘满氧化反应中的催化性能

使用接枝法将介孔分子筛MCM-41官能团化,进而利用负载官能团与氯化铜的配位实现氯化铜在MCM-41上的组装,得到了2个新型多相化催化剂。采用FT-IR、UV-Vis、AAS、XRD以及N2吸附等方法对其进行了表征,考察了多相化催化剂对叔丁基过氧化氢氧化萘满生成1-四氢萘酮反应的催化性能。结果表明,多相化催化剂在首次使用中表现出较好的催化活性,但是循环使用情况较差。     

CO2 adsorption on systems involving ethylenediamine impregnated on nanoporous materials

Abstract

MCM-41 and MCM-48 materials were synthesized by the hydrothermal method, calcined and modified with ethylenediamine (EDA) by wet impregnation method. The X-ray diffraction patterns showed characteristic peaks of highly ordered MCM-41 and MCM-48 nanoporous materials, even after impregnation with amine. The MCM-41 and MCM-48 materials showed N₂ adsorption isotherms type IV and BET surfaces areas higher than 1000?m² g^?1. The carbon dioxide adsorption tests were carried out at room temperature in a magnetic suspension microbalance. The materials presented good performance for CO₂ capture, being favorable for applications where medium and high pressures are required.     

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。     

L/MCM-41介微孔复合分子筛合成的影响因素

以十六烷基三甲基溴化铵（CTAB）为模板剂,采用两步晶化法先合成L分子筛,再合成 L/MCM-41复合分子筛,合成过程中采用了离子交换技术。用 XRD、BET 等测试手段对合成样品进行表征。考察了合成体系pH值、模板剂用量、晶化温度对合成产物的影响。结果表明,用硫酸调节合成体系 pH 值在10~11范围,以及 n(CTAB)/n(SiO₂)=0.25、120℃ 晶化2 d 的条件下,合成得到的 L/MCM-41复合分子筛孔径比微孔分子筛大,为3.04 nm;与水热晶化法合成的MCM-41相比,壁厚由0.55 nm 增大到1.81 nm;水热稳定性也明显提高,在100℃沸腾状态下结构保持时间由原来的低于2 h 延长到8 h。     

Catalysed oxidation of quinoline in model fuel and the selective extraction of quinoline-N-oxide with imidazoline-based ionic liquids

Synthesised vanadium-coordinated N,N-bis(o-hydroxybenzaldehyde)phenylene diamine catalyst, [VO(sal-HBPD)] and supported catalyst, p[VO(sal-HBPD)] were employed for the oxidation of quinoline. The use of [VO(sal-HBPD)] and p[VO(sal-HBPD)] for the oxidation of quinoline, (Quinoline-to-H₂O₂ ratio 1:7) showed oxidation selectivity as quinoline-N-oxide (100%) was recorded as the oxidation product. Quinoline-N-oxide was confirmed as the oxidation product through GC–MS. Density functional theory (DFT) revealed hydroxylperoxido-species [VOO(sal-HBPD)] (II) as the reactive oxidized oxidovanadium specie responsible for the oxidation. Ionic liquids, 1-butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium nitrate extracted 96% and 87% quinoline-N-oxide respectively.     

H6P2W18O62/MCM-48催化剂的制备、表征及催化绿色合成己二酸

以MCM-48为载体,通过浸渍法制备了H6P2W18O62/MCM-48催化剂,并采用FT-IR、XRD、SEM、EDS对催化剂进行表征。以微波促进30%(质量分数)H2O2氧化环己酮合成己二酸反应为探针,考察了H6P2W18O62/MCM-48的催化性能,并通过正交实验确定了优化的工艺条件。结果表明,采用H6P2W18O62负载量40%的H6P2W18O62/MCM-48催化剂,在优化的合成己二酸的工艺条件下,即催化剂质量分数(以环己酮质量计)5.1%、n(C6H10O)∶n(H2O2)∶n(H2C2O4.2H2O)=100∶450∶1.88、反应温度95℃、微波功率300 W、反应时间3.5h,己二酸收率可达81.3%;催化剂重复使用5次,己二酸收率仍可达到64.6%。     

Ru/MCM-41催化剂上苯的液相加氢反应

 以Si-MCM-41、Al-MCM-41(1) (n(Si)/n(Al)=15)、Al-MCM-41(2) (n(Si)/n(Al)=10)以及用NH4NO3或HAc的醇溶液分别与Si-MCM-41离子交换所得的H-MCM-41(N)和H-MCM-41(H)为载体制备了系列Ru/MCM-41催化剂。采用N2吸附、XRD和H2-TPR表征了负载Ru前后催化剂的结构及Ru在各种载体表面上的分散状态。以0.5%（质量分数）苯的环己烷溶液为模型化合物，在298K、3.0MPa反应条件下，考察了上述催化剂的苯液相加氢反应性能，并与Ru/HY、Ru/H和Pt/MCM-41催化剂进行了比较。结果表明，载体MCM-41的n(Si)/n(Al)和表面化学组成等性质对Ru在其表面上的分散状态、还原性及催化性能均有影响。对苯的转化率与反应时间的关系曲线进行拟合，发现其遵循一级动力学方程，加氢反应速率常数按照Ru/Al-MCM-41(2)相似文献   

Physicochemical Properties and Catalytic Performance of a Novel Aluminosilicate Composite Zeolite for Hydrocarbon Cracking Reaction

A novel micro-micro/mesoporous aluminosilicate ZSM-5-Y/MCM-41 composite molecular sieve with a MCM-41 type structure was synthesized through a novel process of the self-assembly of CTAB surfactant micellae with silica-alumina source originated from alkaline treatment of ZSM-5 zeolite.The physical properties of the ZSM-5- Y/MCM-41 composite molecular sieve were characterized by XRD,Py-FTIR and N_2 adsorption-desorption techniques. Different kinds of molecular sieves including ZSM-5,Y zeolite,Al-MCM-41,ZSM...     

新型超大孔沸石分子筛的合成和应用

九十年代初新发展的超大孔分子筛ＭＣＭ－４１,它的孔径远远超过目前小于１．２ｍｍ的微孔分子筛如Ｘ,Ｙ,,丝光沸石和ＺＳＭ－５沸石。由于它的均匀大孔结构和较好的酸性可以应用于重油加工和大分子 细化工反应,是当前国内外沸石研究热点课题。