溶胶-凝胶法有机-无机精细复合材料P(VDF/TeFE)-SiO_2的制备与显微结构

用溶胶－凝胶法制备了有机－无机精细复合材料Ｐ（ＶＤＦ／ＴｅＦＥ）－ＳｉＯ２。利用水解－聚合反应由正硅酸乙脂（ＴＥＯＳ）合成ＳｉＯ２溶胶，乙醇作溶剂，盐酸作催化剂。将Ｐ（ＶＤＦ／ＴｅＦＥ）溶于丙酮，并与ＳｉＯ２溶胶均匀混合。凝胶后经干燥和热处理得到有机－无机精细复合材料Ｐ（ＶＤＦ／ＴｅＦＥ）－ＳｉＯ２。用红外光谱分析、扫描电镜分析、差示扫描热分析和热失重分析对有机－无机精细复合材料Ｐ（ＶＤＦ／ＴｅＦＥ）－ＳｉＯ２进行了显微结构表征。     

ZrO2-SiO2膜的制备和结构研究

以正硅酸乙酯和氧氯化锆为原料,用溶胶－数胶法制备了无支撑ＺｒＯ２－ＳｉＯ２膜。应用ＤＴＡ－ＴＧ、ＸＲＤ－ＳＥＭ和ＢＥＴ等测试技术对无支撑ＺｒＯ２－ＳｉＯ２膜结构、表面形貌和孔径进行了表征,结果ＺｒＯ２－ＳｉＯ２凝胶膜虽在４６７℃开始出现少量单斜ＺｒＯ２,但在５００℃和１２００℃热处理后的晶相均为四方ＺｒＯ２显然ＳｉＯ２的存在的ＺｒＯ２－ＳｉＯ２膜具有比ＺｒＯ２膜同的热稳定性,在９５０℃欧下发人头发     

低硅沸石骨架结构及其稳定性的模拟计算

采用晶格能极小化技术模拟计算了一系列结构的低硅沸石全硅骨架晶格,预测了它们的骨架结构和晶格能．计算结果与二氧化硅致密α一石英相比较,发现这些低硅沸石彼此间的晶格能相差很小（＜２５ｋＪ·ｍｏｌ^－１）,与α一石英相差４３～６８ｋＪ·ｍｏｌ^－１这意味着在低硅沸石的合成中,特定结构骨架的形成仅需要较少的能量;可以解释低硅沸石骨架结构的相似性和多样性．同时讨论了计算晶格能和骨架结构间的关系,结果表明随着低硅沸石骨架密度的增大,全硅骨架晶格能呈降低趋势．分析这些低硅沸石的ＸＲＤ数据发现在它们的结构中包含较短的 Ｓｉ－Ｏ键长（０．１５５７ｎｍ）,很长的 Ｓｉ－Ｏ键长（０１７６４ｎｍ）, Ｏ－Ｓｉ－Ｏ键角有大的分布范围（９３．３８～１３３．４１°）,Ｓｉ－Ｏ－Ｓｉ键角平均在１４４°左右并且具有更大的分布范围（１２７～１８０°）。     

溶胶—凝胶法有机—无机精细复合材料P（VDF／TeFE）—SiO2的制备与显微 …

用溶胶－凝胶法制备了有机－无机精细复合材料Ｐ（ＶＤＦ／ＴｅＦＥ）－ＳｉＯ２。利用水解－聚合反应由正硅酸乙酯（ＴＥＯＳ）合成ＳｉＯ２溶胶，乙醇作溶剂，盐酸作催化剂。将Ｐ（ＶＤＦ／ＴｅＦＥ）溶于丙酮，并与ＳｉＯ２溶胶均匀混合。凝胶后经干燥和热处理得到有机－无机精细复合材料Ｐ（ＶＤＦ／ＴｅＦＥ）－ＳｉＯ２。用红外光谱分析、扫描电镜分析、差示扫描热分析和热失重分析对有机－无机精细复事材料Ｐ（ＶＤＦ／ＴｅＦ     

水热合成纳米硅酸锆工艺因素分析

通过正交实验并借助于ＸＲＤ 和ＴＥＭ 等手段,研究了前驱物配比、反应温度、反应时间、升温速率等工艺因素对水热合成纳米ＺｒＳｉＯ４ 的影响。结果表明：前驱物配比、反应温度、反应时间及升温速率是影响纳米ＺｒＳｉＯ４ 粉体合成的主要因素,同时,当前驱物ｍ（Ｚｒ）∶ｍ（Ｓｉ）＝ １－２∶１－０ ,反应温度为３３５ ℃,反应时间为４ｈ,升温速率为１－６ ℃／ｍｉｎ 时,可制得晶粒规整、分散性好、粒度在１００ｎｍ 以下的ＺｒＳｉＯ４ 粉体。     

二氧化硅气凝胶合成新工艺

以Ｅ－４０（多聚硅氧烷）为硅源,以ＨＦ为催化剂,用溶胶－凝胶法制备出了ＳｉＯ２气凝胶法时研究了催化剂、溶剂、水等制备因素对其溶胶－凝胶过程的影响,用孔径分布测定仪、透射电镜（ＴＥＭ）、比表面测试（ＢＥＴ）等方法对其微结构进行了研究。研究结果表明,ＨＦ的加入大大加束字溶胶－凝胶反应速度;ＢＥＴ以及ＴＥＭ测试结果表明所制备的ＳｉＯ２气凝胶具有大的比表面积和纳米多孔结构（骨架颗粒约为１０纳米,孔洞尺政变     

核壳结构型纳米CaCO3-SiO2.nH2O复合粒子的制备

在搅拌槽式反应器中,以用超重力法合成的纳米 ＣａＣＯ３和 Ｎａ２ＳｉＯ３为原料,用溶胶－凝胶技术制备具有核壳结构的纳米 ＣａＣＯ３－ＳｉＯ２·ｎＨ２Ｏ复合粒子　用 ＸＰＳ、 ＴＥＭ、 ＸＲＤ等方法对粒子的化学组成、形貌、晶型等作了分析和表征     

SiC－AlN－Y_2O_3复相陶瓷的制备与性能

通过热压烧结技术，ＳｉＣ、ＡｌＮ和Ｙ２Ｏ３粉末混合作在１９２０～２０５０℃、Ａｒ气氛下形成了致密的复相陶瓷．在室温下ＳｉＣ－ＡｌＮ－Ｙ２Ｏ３复相材料的抗弯强度和断裂韧性分别达到６００ＭＰａ和７ＭＰａ·ｍ１／２以上运用ＸＲＤ、ＳＥＭ和ＴＥＭ分析致密样品的断裂裂纹、形貌和组成．ＳｉＣ－ＡｌＮ－Ｙ２Ｏ３复相陶瓷在１３７０℃氧化试验３０ｈ，其氧化产物为莫来石．     

溶胶—凝胶制备TiO2／SiO2复合薄膜的FT—IR表征

ＦＴ－ＩＲ吸收谱用来研究具有多孔结构的ＴｉＯ２／ＳｉＯ２复合薄膜；薄膜在１２００ｃｍ＾－１有一较强的肩峰，其强度与峰位随热处理温度度而生变化。在９５５ｃｍ＾－１的吸收峰是由于Ｓｉ－Ｏ－Ｔｉ和Ｓｉ－ＯＨ的结果，并随着热处理 度的提高其吸收峰完全是Ｓｉ－Ｏ－Ｔｉ振动所引起的，其峰位随着ＴｉＯ２的增加，向低频区域移动。     

SiC—AlN—Y2O3复相陶瓷的制备与性能

通过热压烧结技术，ＳｉＣ、ＡｌＮ和Ｙ２Ｏ３粉末混合体在１９２０￣２０５０℃、Ａｒ气氛下形成了致密的复相陶瓷。在室温下ＳｉＣ－ＡｌＮ－Ｙ２Ｏ３复相材料的抗弯强度和断裂韧性分别达到６００ＭＰａ和７ＭＰａ·ｍ＾１／２以上。运用ＸＲＤ、ＳＥＭ和ＴＥＭ分析致密样品的断裂裂纹、形貌和组成。ＳｉＣ－ＡｌＮ－Ｙ２Ｏ３复相陶瓷在１３７０℃氧化试验３０ｈ，其氧化产物为莫来石。     

用沉淀二氧化硅合成钛硅分子筛TS-2的研究

以沉淀二氧化硅为硅源,钛酸四丁酯为钛源,四丁基氢氧化铵为模板剂,采用水热晶 化法合成了TS-2分子筛.在优化合成步骤的基础上,采用XRD、FT-IR、UV-Vis、SEM 等测试方法系统研究了晶化温度、凝胶Si／Ti对晶化动力学行为及TS-2分子筛晶相结构的影 响.结果表明:高纯TS-2分子筛的最佳晶化温度为175℃,过高的晶化温度易导致MEL结构 向MFI晶相结构的转变及晶粒的逐渐长大.高纯TS-2样品的极限Ti／Si值为0.04,高于此值 则生成非骨架钛氧化物,并造成相对结晶度和催化氧化性能显著降低.     

Synthesis,characterization, and catalytic properties of titanium silicates prepared using phosphonium ions

A titanium silicate has been synthesized in the presence of tetrabutylphosphonium ions. X-ray diffraction has revealed that this solid was identical to the already reported TS-2, with the MEL structure. The rate of crystallization of the zeolite as well as the maximal amount of Ti atoms that can be incorporated in the lattice are specific of the template. When the synthesis is carried out under stirring conditions, the size of the crystals is comparable to that of a standard TS-2. For similar Ti contents, the catalytic activities and selectivities in the hydroxylation of phenol with hydrogen peroxide are identical.     

添加有机胺对钛硅沸石的合成和催化性能的影响

在用合成TS-2后的过滤液（简称母液）添加其它有机胺作模板剂合成钛硅沸石的研究中,发现添加四乙基氢氧化铵（TEAOH）溶液有促进TS-2沸石晶粒显著长大和骨架钛含量提高的作用;加乙二胺使合成的TS-2中混有少量的TS-1杂晶;加入正二丙胺合成的沸石已完全转晶为TS-1,而且其晶体形貌也有显著的改变．这种添加效应进而影响钛硅沸石作为苯酚羟基化的氧化催化剂和作为氧化苯乙烯重排反应的弱酸催化剂的催化性能．     

负载型TS-1沸石膜催化剂的制备、表征及其催化性能研究

利用水热合成法在α-Al₂O₃陶瓷管表面制备了连续完整的钛硅(TS-1)沸石膜, 并且利用该膜催化剂催化丙烯直接环氧化合成环氧丙烷(PO)。采用SEM、XRD、FT-IR和UV-Vis等表征手段及丙烯环氧化反应测试, 详细研究了合成液中Ti/Si比对TS-1沸石膜形貌、结构及催化性能的影响。结果表明, 合成液中Ti/Si比在0.01~0.04范围内, 所合成的TS-1沸石膜均具备典型MFI型拓扑结构。但当Ti/Si比>0.02时, 随着Ti/Si比升高, TS-1沸石膜表面沸石颗粒排列变得杂乱, 且TS-1沸石沉积量逐渐减少, 沸石晶间缺陷增多, 丙烯渗透速率增大。而且, 当Ti/Si比= 0.03、0.04时, 由于所合成的TS-1沸石膜中存在大量非骨架钛, 导致在丙烯环氧化反应中PO选择性和PO生成速率明显降低。当Ti/Si比为0.02时, 合成的TS-1沸石膜骨架钛含量最高, 其催化性能最佳, H₂O₂转化率、PO选择性和生成速率分别为12.43%、95.80%和15.78 mmol/(h·g)。TS-1沸石膜在丙烯环氧化反应中重复使用8次, 其催化性能保持相对稳定。     

Characterization of TS-1 synthesized using mixtures of tetrabutyl and tetraethyl ammonium hydroxides

The titanium silicalite TS-1, which was generally synthesized using tetrapropylammonium hydroxide (TPAOH) as the templating agent, has been prepared using mixtures of tetrabutylammonium hydroxide (TBAOH) and tetraethylammonium hydroxide (TEAOH). TBAOH is known to direct the MEL structure. When more than 20% of TBAOH was replaced by TEAOH, pure TS-1 was obtained. ¹³C CP/MAS n.m.r. has shown that TBA⁺ and TEA⁺ cations were incorporated intact into the structure during crystallization, in the following proportions TBA/TEA = 1. This material has proved to have similar catalytic properties as a standard TS-1 in the hydroxylation of phenol with hydrogen peroxide.     

晶粒大小对钛硅分子筛TS-1催化氧化活性的影响

采用改进后的水热晶化法合成了TS-1分子筛,研究了凝胶pH值、硅源类型对TS-1分子筛晶粒度、晶化动力学及其催化氧化性能的影响.结果表明,选择有机硅源并采用较高的凝胶pH值有利于合成晶粒较小的TS-1分子筛.有机硅源TEOS与无机硅源的晶体生长活化能的显著差异决定了合成TS-1分子筛晶粒度大小的不同.TS-1催化的氧化反应受分子筛孔内扩散的限制,晶粒越小,表面利用率越高,因而其催化氧化活性越高.     

VTS-2分子筛的合成、表征与催化氧化性能

分别以TBOT、VOSO4.3H2O、TEOS为钛源、钒源和硅源,TBAOH为模板剂,异丙醇为溶剂,采用水热晶化法,在Si/(Ti+V)≥33(凝胶中)条件下合成了具有MEL拓扑结构,骨架含两种不同价态过渡金属钛、钒的杂原子分子筛VTS-2。采用XRD、FT-IR、UV-Vis、EDS及催化反应等方法测试了所合成分子筛的晶相结构、波谱性质和催化氧化性能。对苯乙烯催化氧化反应的评价结果显示,在骨架金属含量相近的情况下,骨架含钛、钒两种过渡金属的VTS-2分子筛对烯烃的催化氧化活性分别高于骨架含单一金属的TS-2和VS-2,表明金属钒的引入有助于提高TS-2分子筛的催化氧化活性,调节氧化产物分布。     

Synthesis of framework-substituted Fe-HMS and its catalytic performance for phenol hydroxylation

The iron-incorporated mesoporous silica material Fe-HMS was successfully synthesized at ambient temperature by using dodecylamine as the template agent, and it was characterized by XRD, SEM, FT-IR, UV-vis, ESR and N(2) adsorption measurements. Its catalytic performance was studied for phenol hydroxylation with H(2)O(2) in a fixed-bed reactor. The results show that Fe(3+) ions have been successfully incorporated into the framework of HMS, and Fe-HMS has a uniform mesoporous structure with about 2.7?nm pore diameter. After Fe-HMS is calcined, most of the Fe(3+) ions remain in the tetrahedral coordinated framework, and only a small part of Fe species migrate to the extraframework. Fe-HMS has high catalytic activity and very high selectivity to dihydroxybenzene for the hydroxylation of phenol. Over the Fe-HMS catalyst, the product distribution of phenol hydroxylation is different from that over the microporous TS-1 zeolite. The solvents have great influence on the catalytic activity of Fe-HMS, and water is the best solvent.     

Synthesis and catalytic ammoxidation performance of hierarchical TS-1 prepared by steam-assisted dry gel conversion method: the effect of TPAOH amount

The hierarchical titanium silicalite-1 (TS-1) was synthesized by the steam-assisted dry gel conversion method in one step and characterized by XRD, SEM, N₂ adsorption/desorption, UV–Vis, FT-IR, and Raman spectroscopies. And its catalytic activity was tested for ammoxidation of methyl ethyl ketone with hydrogen peroxide as oxidant. The results show that the amount of tetrapropylammonium hydroxide (TPAOH) as template has a major influence on the physicochemical and catalytic properties of the hierarchical TS-1 prepared. When lower amount of TPAOH (TPAOH/SiO₂ = 0.08 mol) was used, hierarchical TS-1 can be successfully synthesized. With an increase in TPAOH amount in synthesis solution, the crystal size of TS-1 is decreased and mesoporous surface area is increased; if the excess template was used in the synthesis of TS-1, more extra-framework Ti would be formed in the TS-1 samples prepared. The hierarchical TS-1 exhibits higher catalytic activity than TS-1 prepared hydrothermally for ammoxidation of methyl ethyl ketone. Using hierarchical TS-1 synthesized under TPAOH/SiO₂ = 0.18 as the catalyst, which has more tetrahedrally coordinated Ti species in the TS-1 framework, 94.2 % conversion of reactant and 100 % selectivity to methyl ethyl ketone oxime can be obtained after 2 h of reaction at 70 °C.     

Synthesis of dendritic TS-1 film on honeycomb cordierite

With a unique crystallization and aging procedure, the dendritic TS-1 film was synthesized on a honeycomb cordierite surface by hydrothermal method. The loose dendrite morphology was presented in SEM photos, and the “branches” were comprised of oriented stacked TS-1 crystals with a uniform particle size about 200 × 500 nm; some characteristic FT-IR peaks were highlighted after calcination for the removal of the template reagent. The dendritic TS-1 film performed better catalytic activity than the general TS-1 film with dense planar morphology in the ammoximation reaction of cyclohexanone and ammonia.