二异丙苯和苯烷基转移反应中Y型沸石催化剂的研究

采用水热处理与离子交换结合的方法对ＮａＹ沸石进行了改性，ＸＲＤ、ＸＰＳ及孔结构测试结果表明，ＮａＹ沸石经水热处理和离子交换改性制得的Ｙ沸石催化剂的晶体晶型未发生变化；处理温度对催化剂的相对结晶度、孔结构及比表面积有很大影响；水热处理可以使微孔孔口啼生缺陷或破裂；在一定温度下，催化剂能够形成二次孔；过高的处理温度将导致催化忆结构的崩坍，Ｙ沸石催化剂存在铝富集在表面的现象，采用左外光谱及哟啶，２，６－     

碱性水蒸气处理的ZSM-5沸石酸性质及孔结构的影响

 采用XRD，NH3－TPD，比表面积和孔结构测定等研究了在不同温度下用含10％NH3的水蒸气处理时HZSM－5沸石n（Si）／n（Al）＝25）酸性质及孔结构的变化规律．结果表明，随着处理温度的提高，HZSM－5的结构未发生明显的变化；样品的总酸量下降很快，但弱酸分布量相对提高，而强酸分布量相对下降；提高处理温度，样品的比表面积和微孔体积减小，二次孔或中孔体积及外表面积有增大的趋势．     

水热处理USY二次孔形成规律研究

研究了氧化钠含量不同Y型分子筛水热处理形成二次孔的规律.结果表明，NH4NaY升温至650 ℃,分子筛处于介稳态，其比表面积、孔容等均显著低于NaY.红外研究未发现脱铝及其他物种生成,通入水蒸气后,有脱铝过程发生，但其比表面积、孔容等大幅增加,总孔容也大于NaY；进一步处理上述参数又有降低.这种变化被归结为升温形成的具有强电子亲和势的质子在高温下和骨架氧发生强相互作用,造成骨架扭曲、松弛或断裂,而有Na＋存在的方钠石笼则保持相对稳定.在高温水热合成条件下,可能以稳定的方钠石笼为单位进行结构重排,骨架脱铝形成的非骨架铝和无定形氧化硅物种的存在,抑制了分子筛按照原始NaY的结构愈合,只能形成具有破损方钠石笼（缺陷）的八面沸石结构,这可能是二次孔形成的原因.     

改性Y沸石的孔结构与催化性能

测定了不同方法改性的Y沸石样品的N_2吸附和脱附等温线, 并计算了样品的微孔、大孔和二次孔的孔容和表面积, 以及样品的二次孔分布, 证实改性方法对样品的孔结构有显著的影响。同时, 还考察了不同尺码探针分子在改性Y沸石样品上的酸催化反应活性, 将所得数据与样品的酸量、酸强度和二次孔容相关联, 取得了满意的结果。说明对大尺码反应分子, 改性过程中生成的大孔径二次孔, 对提高沸石催化剂的反应活性是有利的。     

不同方法制备的脱铝Y沸石的孔结构

Y沸石脱铝有多种方法。由于在脱铝过程中发生水解、聚合、重排等反应,分子筛的孔结构将发生很大的变化,如形成空穴,甚至可导致骨架结构单元的崩塌,形成二次孔。由于不同的脱铝方法的脱铝机理不同,即使它们的脱铝程度一致,产生的孔结构也将不同,这必将导致它们的酸性质和催化性能的差异。目前关于Y沸石孔结构的研究报导还很少,尤其对SSY,US-SSY沸石孔结构的报导更为鲜见。本文用低温N_2吸附-脱附等温线和层厚t等方法,对四种不同方法制备的脱铝Y沸石(USY,DAY,SSY和US-SSY)的微孔、二次孔及其孔径分布(2.0～60.0nm)进行了初步研究,得到了一些有用的信息,为进一步研究其酸性质和催化性能打下了基础。     

介孔高硅Y沸石的合成及催化裂化性能（英文）

Y型沸石拥有三维十二元环孔道(孔径0.74 nm)以及超笼结构(直径1.12 nm),在石油冶炼、石油加工、精细化学品合成以及新兴生物油的炼制方面具有重要应用.研究表明,随着Y沸石骨架硅铝比(SiO₂/Al₂O₃,简称SAR)提高,酸中心强度增加,酸密度降低,有助于抑制裂化反应中积碳导致催化剂的失活,并提高催化剂活性;另外,随着沸石骨架硅铝比提高,Y沸石对应热/水热稳定性相应增加,有利于保持催化剂长周期使用性能.Y沸石的大孔结构使其在工业应用中有着显著的优势,然而对于大分子反应物,反应物与沸石内部活性位点的接触以及相应的产物扩散仍限制了其催化性能.介孔沸石同时具有微孔和介孔两类孔道结构,可以克服微孔沸石有限孔径尺寸带来的传质限制,进一步提高反应性能.现在工业上应用的高硅Y沸石均是通过酸脱铝,水蒸汽辅助脱铝等后处理方法获得.虽然后处理过程可以提高沸石骨架硅铝比,并引入适量的介孔结构,改善其在催化裂化反应中的传质性能,但后处理过程工序复杂,耗时耗能,而且会形成脱铝梯度,不利于其催化应用.相对而言,直接合成介孔高硅Y沸石是最理...     

碱处理脱硅与提高Y型分子筛硅铝比——矛盾的对立与统一

考察了 "水热处理"以及"碱处理+水热处理"两种方法所制得的超稳 Y 分子筛的骨架硅铝比、孔结构特征以及酸量, 并探讨了"碱处理+水热处理"方法对起始 NaY 分子筛的适应性. 结果表明, 在水热处理前, 对 NaY 分子筛进行碱处理脱硅可在不改变最终样品的骨架超稳化水平和酸量的同时, 样品的介孔体积显著增加. 直接水热处理 NaY 分子筛所得样品介孔体积不超过 0.14 cm3/g, 而先碱处理后水热处理, 所得样品介孔体积可达 0.22 cm3/g. 该法适用于制备骨架硅铝比高的 NaY 分子筛. 起始原料的骨架硅铝比较低时, 所得样品的介孔体积增幅小, 而且微孔受损严重.     

大比表面积炭质吸附剂的表面及孔隙发展

以石油焦为原料研究了采用KOH活化法制备大比表面积炭质吸附剂时表面及孔隙的发展。实验发现虽然KOH加入量 ,水乙醇溶液中乙醇含量和提高热处理终温以及延长热处理时间都使比表面积增大 ,但是水乙醇加入总量的增加则导致比表面积下降。KOH加入量以 60～ 75%为宜 ,此时其利用率在 40 0m2 g以上。孔隙分布研究表明水乙醇加入总量 ,乙醇含量和热处理温度的提高都使 1～ 2nm微孔孔容及其在 1～ 2 0nm微孔孔容中所占比率增加。实验发现大比表面积炭质吸附剂的比表面积与碘值之间存在一定相关性。由于碘值不存在N2 吸附BET比表面积的过高估计现象 ,因而这给用碘值来更合理评价大比表面积炭质吸附剂的相对吸附能力提供了可能。     

高中油型加氢裂化催化剂用Y型沸石的改性研究

采用络合-水热-酸联合处理的方法对Y沸石进行了改性,改性后的沸石用于制备高中油型加氢裂化催化剂,并考察了沸石改性对高中油型加氢裂化催化剂反应效果的影响。氮吸附、XRD、TEM和吡啶吸附 脱附红外光谱法等表征结果表明,酸处理可以有效脱除分子筛中的非骨架铝,增加改性Y沸石的比表面积和二次孔的孔容,并起到优化酸中心的目的。反应评价结果表明,Y沸石经酸处理改性后,由于比表面积、二次孔孔容的增加和酸性的优化,所制得的催化剂可明显提高高中油型加氢裂化加氢裂化的中油收率。     

REUSY-Ex的吸附性能及二次孔结构研究

应用高真空重量法(分别以苯和正庚烷为吸附质)和低温N2吸附法对REUSY-Ex的吸附性能和二次孔结构进行了研究.结果表明,在水热处理过程中可产生二次孔结构,且二次孔的形成与水热处理的脱铝深度相关.稀HCl浸取REUSY不仅能浸取出位于其二次孔中的非骨架铝(EFAL)碎片,而且还能浸取出位于微孔中的EFAL。29Si MAS NMR的结果显示,稀HCl浸取后,骨架Si(OAl)的谱宽变窄,裂分效果提高,表明其化学环境单一或均匀.     

Influence of chemical dealumination on the properties of USY zeolite

Three series of dealuminated Y zeolites have been prepared by chemical extraction ofhydrothermally dealuminated Y zeolite(USY)with H_2Na_2EDTA,HCl and H_4EDTA.The unitcell constant,mesopore distribution,acidity and extraframework aluminum(EFAL)of thezeolites were studied with XRD,chemical analyses,adsorption,IR and NH_3-TPD techniques.It was shown that H_2Na_2EDTA only removed EFAL species deposited in the pores of USY,by contrast,HCl and H_4EDTA extract both extraframework and framework aluminum,andmake the zeolite framework further dealuminated.Adsorption tests gave evidence that a second-ary pore system exists in these dealuminated zeolites.H_2Na_2EDTA extraction increased bothmicropore and mesopore volumes,but after HCl and H_4EDTA treatments,new mesopores formedand the micropore volume was decreased.The pyridine-IR and NH_3-TPD measurements demon-strated that EFAL had no evident contribution to the zeolite acidity.     

渣油FCC改性Y沸石研究

研究了不同方法和不同程度脱铝对Y型沸石浸镧老化后的结构性质和催化裂化性能的影响。结果表明，氟硅酸铵脱铝补硅和水热处理两个步骤联合，所得样品骨架铝分布均匀，通过控制脱铝程度可更有效地抑制结焦并保持催化裂化高活性；草酸脱铝和水热处理联合，所得样品二次孔结构发达，具有更好的渣油裂化生成液态低碳烃选择性。     

Study on adsorption performance of conjugated microporous polymers for hydrogen and organic solvents: The role of pore volume

A series of homocoupled conjugated microporous polymers (HCMPs) were prepared by cross-coupling polymerization of 1,3,5-triethynylbenzene and 1,4-diethynylbenzene with various monomer molar ratios. Our results show that the molar ratio of monomers has a remarkable influence on the surface area, pore volume, and micropore volume of the as-synthesized HCMP samples. With the increase of molar ratio of 1,3,5-triethynylbenzene to 1,4-diethynylbenzene, the surface area and total pore volume increased while the micropore volume decreased for these HCMP samples. We also investigated the adsorption performance for hydrogen and organic solvents of these HCMP samples. Results obtained from experiments show that the increase of total pore volume (contributed from both mesopore and micropore) of HCMPs would lead to an increase in their adsorption abilities for organic solvents, while hydrogen sorption ability for HCMPs can only be improved by increasing their micropore volume, which may provide useful guidance for the rational design of novel HCMPs with different porosities as absorbent materials for oil/organic solvents or hydrogen storage systems.     

Hydrothermal,microwave and mechanochemical modification of amorphous zirconium phosphate structure

The influence of hydrothermal HTT, microwave MWT and mechanochemical MChT treatments on structure of precipitated amorphous zirconium phosphate has been studied. Using XRF, XRD and DTA-TG techniques, the formation of the low-crystalline zirconium hydrophosphate Zr(HPO₄)₂·H₂O after HTT and MWT has been established. All types of modification promote increase in specific surface area, pore volume and pore size as well as extend the limits of the porous structure parameters variation. MChT of wet gel allow to prepare the samples possessing simultaneously high values of specific surface area, volume and pore size. Total surface acidity significant increases as a result of modification. HTT and MWT as well as MChT of wet gel lead to increasing surface homogeneity as the decrease in fractal dimension for modified samples indicates.     

Micropore modification of zeolites with transition-metal oxides

The micropores of USY and ZSM-5 zeolites were modified with the transition-metal oxides, such as Fe₂O₃, MoO₃ and V₂O₅. The structures of the modified samples were characterized by XRD and the physical features were determined by N₂ adsorption method. The results show that the transition-metal oxides can diffuse well into the micropores of zeolites. The surface area, micropore area, pore volume and typical pore diameter of the modified samples change respectively, and the change might result in a novel process for the design of the shape-selective catalysts and special adsorbents.     

高岭土微球上无胺法ZSM-5的原位合成

无胺体系中,采用水热法在焙烧高岭土微球上原位晶化合成了ZSM-5分子筛。考察了晶化温度、晶化时间、晶种加入量以及合成体系硅铝比等主要因素对分子筛合成的影响,得出了较佳的原位晶化合成条件。采用XRD、SEM、N₂吸附脱附等手段对合成样品进行了表征。结果表明：在高岭土微球上合成出了颗粒尺寸小于1 μm的小晶粒原位ZSM-5分子筛;晶化产物的比表面积、总孔容、微孔表面积和微孔孔容均明显增大,微孔分布集中于0.54 nm。     

二维分子筛的制备及其催化应用研究进展

沸石分子筛是一种具有独特孔道结构的硅铝酸盐晶体,因其具有较大的比表面积、优异的孔道择形性、良好的热稳定性以及适宜的酸性质等特点,被广泛应用于催化、吸附、分离等领域。与常规三维沸石分子筛相比,二维分子筛由于其独特的形貌结构带来的可调变的多级孔结构、适宜的表面酸性以及良好的扩散传质性能等优点,已在吸附和催化领域显示出巨大的应用潜力。本文系统总结了二维MFI、SAPO-34、MCM-n、Y型分子筛等的合成以及此类分子筛催化应用研究方面的最新进展。最后,对二维沸石分子筛材料的新合成方法及新应用领域进行了展望。     

Influence of surface treatments on micropore structure and hydrogen adsorption behavior of nanoporous carbons

The scope of this work was to control the pore sizes of porous carbons by various surface treatments and to investigate the relation between pore structures and hydrogen adsorption capacity. The effects of various surface treatments (i.e., gas-phase ozone, anodic oxidation, fluorination, and oxygen plasma) on the micropore structures of porous carbons were investigated by N(2)/77 K isothermal adsorption. The hydrogen adsorption capacity was measured by H(2) isothermal adsorption at 77 K. In the result, the specific surface area and micropore volume of all of the treated samples were slightly decreased due to the micropore filling or pore collapsing behaviors. It was also found that in F(2)-treated carbons the center of the pore size distribution was shifted to left side, meaning that the average size of the micropores decreased. The F(2)- and plasma-treated samples showed higher hydrogen storage capacities than did the other samples, the F(2)-treated one being the best, indicating that the micropore size of the porous carbons played a key role in the hydrogen adsorption at 77 K.