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41.
42.
介孔分子筛MSU-1的合成 总被引:1,自引:0,他引:1
MSU X介孔分子筛具有三维立体交叉排列的蠕虫状孔道结构,有利于客体分子在其孔道内扩散[1]。目前合成MSU X的原料[2 4]TEOS水解速度慢,合成过程较易控制,但价高、易燃、有刺激性。本文采用文献[5 7]法,以水玻璃、A(EO)9为原料,在酸性至近中性的范围里合成了MSU 1介孔分子筛,与TEOS为原料的MSU 1合成进行了比较,考察了pH值和不同类型表面活性剂(脂肪醇聚氧乙烯醚和烷基酚聚氧乙烯醚)对产物结构性质的影响。1 实验部分1 1 试剂和仪器水玻璃(SiO2%≈26、Na2O%≈8),工业级,青岛海洋化工厂生产;脂肪醇聚氧乙烯醚非离子表面活性… 相似文献
43.
《Mendeleev Communications》2020,30(1):119-120
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44.
Wang X Yu JC Yip HY Wu L Wong PK Lai SY 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(10):2997-3004
A novel metal/semiconductor nanocomposite with catalytic and photocatalytic functions has been prepared. The new material consists of highly dispersed platinum (Pt) nanoparticles embedded in a cubic mesoporous nanocrystalline anatase (meso-nc-TiO2) thin film. The porous thin film possesses a narrow pore-size distribution and a large surface area. The diameter of the Pt cluster can be controlled to below 5 nm, and the high dispersion of these clusters gives rise to catalytic activity for the oxidation of carbon monoxide, an important reaction for automobile exhaust treatment. This novel ordered mesoporous Pt/TiO2 nanoarchitecture is also a promising photochemical material, as demonstrated by the photo-driven killing of Micrococcus lylae cells on the film. 相似文献
45.
Lingping Wang Aiguo Kong Bo Chen Hanming Ding Yongkui Shan Mingyuan He 《Journal of molecular catalysis. A, Chemical》2005,230(1-2):143-150
Transition metal copper substituted mesoporous silica (Cu-SBA-15) was synthesized using triblock copolymers surfactant as template agent under acidic condition. The result Cu-SBA-15 was characterized with XRD, ICP-AES, FT-IR and N2 adsorption–desorption measurements, which prove that Cu(II) was mainly incorporated into the framework of Cu-SBA-15. Its catalytic activity was studied for phenol hydroxylation using H2O2 (30%). The substituting element (Cu2+) is incorporated into the framework position forming a new type of active site which raises the phenol conversion to 62.4% and the diphenol (the mixture of catechol (CAT) and hydroquinone (HQ)) selectivity to 97%. The Cu-SBA-15 has very high selectivity for catechol (about 71% selectivity), which is completely different from that of the microporous titanium silicalite zeolites (47.1% phenol conversion and about 50% selectivity to CAT under same reaction conditions). The results obtained indicate that the selective oxidation of phenol with H2O2 by a radical substitution mechanism. 相似文献
46.
Pyrocarbon/silica gel adsorbents (carbosils, CS) with mesoporous Si-60 (Merck, granule size 0.2–0.5 mm) modified by pyrolysis of CH2Cl2 at 823 K and reaction time from 0.5 to 6 h and then hydrothermally treated at 473 K for 6 h were studied by means of TEM, adsorption and 1H NMR methods. Changes in the structural and adsorptive characteristics of hybrid adsorbents before and after hydrothermal treatment, which depend on pyrocarbon content (C
C), were analyzed on the basis of TEM micrographs and p-nitrophenol and nitrogen adsorption isotherms treated using a constrained regularization method. Interfacial water layers in aqueous suspension of CS were investigated by means of 1H NMR with freezing-out of bulk water at T < 273 K showing nonlinear changes in the Gibbs free energy of interfacial water with increasing C
C because of nonlinear dependence of the structural characteristics of pyrocarbon deposits and CS as a whole on C
C. 相似文献
47.
A. Ungureanu H. V. Thang D. Trong On E. Dumitriu S. Kaliaguine 《Journal of Thermal Analysis and Calorimetry》2007,87(2):417-422
UL-ZSM-5 materials have been prepared by templated solid-state crystallization of zeolites starting from the amorphous mesostructured aluminosilicate Al-Meso. Microcalorimetry and FTIR have been employed to characterize their surface acidity. In good agreement with 27Al MAS NMR data, UL-ZSM-5 displayed an improved density and strength of Brönsted acid sites, as compared to Al-Meso, owing to the incorporation of aluminium in a tetrahedral environment similar to that of zeolite ZSM-5. Moreover, they showed an enhanced Brönsted/Lewis relative acid ratio. However, Al-Meso showed the highest concentration of strong Lewis acid sites due to its largest amount of aluminium in extraframework positions. 相似文献
48.
Cimpeanu V Parvulescu VI Amorós P Beltrán D Thompson JM Hardacre C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(18):4640-4646
Heterogeneous catalytic oxidation of a series of thioethers (2-thiomethylpyrimidine, 2-thiomethyl-4,6-dimethyl-pyrimidine, 2-thiobenzylpyrimidine, 2-thiobenzyl-4,6-dimethylpyrimidine, thioanisole, and n-heptyl methyl sulfide) was performed in ionic liquids by using MCM-41 and UVM-type mesoporous catalysts containing Ti, or Ti and Ge. A range of triflate, tetrafluoroborate, trifluoroacetate, lactate and bis(trifluoromethanesulfonyl)imide-based ionic liquids were used. The oxidations were carried out by using anhydrous hydrogen peroxide or the urea-hydrogen peroxide adduct and showed that ionic liquids are very effective solvents, achieving greater reactivity and selectivity than reactions performed in dioxane. The effects of halide and acid impurities on the reactions were also investigated. Recycling experiments on catalysts were carried out in order to evaluate Ti leaching and its effect on activity and selectivity. 相似文献
49.
A series of carbon-covered titania (CCT) were prepared via pyrolysis of sucrose highly dispersed on titania surface in flowing
N2. The samples were characterized by XRD, BET, DTA-TG, UV—Vis, and their photocatalytic properties were evaluated with two
model pollutants, methylene blue (MB) and rhodamine B (RB), at room temperature. The effect of carbon content on photocatalytic
activity of the C/TiO2 composite was investigated. It was found that the effect of carbon content is different for different pollutants or different
light sources. For three tested samples, under UV illumination CCT01 has the highest activity for MB photocatalytic degradation,
while in the case of RB, CCT02 is the most active photocatalyst. Under visible light illumination, CCT005 has the highest
activity for both MB and RB photocatalytic degradation.
Translated from Chinese Journal of Catalysis, 2006, 27(1): (in Chinese) 相似文献
50.
Mingdeng Wei Kiyomi Okabe Hironori Arakawa Yesutake Teraoka 《Reaction Kinetics and Catalysis Letters》2002,77(2):381-387
SiO2 was modified by hexagonal mesoporous silica to form a mixture with meso-/macroporous sizes and used as support of Co catalysts for Fischer-Tropsch synthesis in a slurry phase. A synergistic effect on the activity of Co catalyst was found. The catalytic properties are related to the state of surface Co and the character of support. 相似文献