共查询到20条相似文献,搜索用时 15 毫秒
1.
F. M. Bobonich V. V. Kovalenko G. M. Tel'biz V. G. Il'in 《Theoretical and Experimental Chemistry》2005,41(4):235-240
The effect of the addition of metal salts and their complexes on the structure, porosity, and stability of MCM-41, added to
the reaction mixture or during removal of the template from the mesophases after synthesis, was investigated. It was established
that additions of inorganic salts reduce the compression of the structure during thermal removal of the template. The relation
between the compression effect and the hydrolytic stability of MCM-41 is examined.
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Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 225–230, July–August, 2005. 相似文献
2.
Yu. G. Gol'tsov Z. V. Smelaya L. A. Matkovskaya V. G. Il'in 《Theoretical and Experimental Chemistry》1999,35(3):179-182
The possibility of synthesizing mesoporous substances in silicate and aluminosilicate systems in the presence of combinations
of glucose oxidase and cetyltrimethylammonium bromide has been demonstrated. Highly crystalline mesoporous molecular sieves
of type MCM-41 with a high aluminum content were obtained from the aluminosilicate system with a reaction mixture pH close
to neutral.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039,
Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 3, 190–193, May–June, 1999. 相似文献
3.
F. M. Bobonich A. S. Kovalenko Yu. G. Voloshina V. N. Solomakha A. S. Korchev A. P. Filippov V. G. Il'in 《Theoretical and Experimental Chemistry》1999,35(6):343-347
Template containing materials of type MCM-41 have properties of microporous substances. On absorption into the micropores
of such materials the dependence of the characteristic absorption energies on the molecular mass of the sorptive is extreme,
and the specific absorption volume decreases with increased molar volume of the sorptive. A model is proposed to explain the
peculiarities of the absorption properties of the template containing materials.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine 31 Prospekt Nauki, Kiev 252039,
Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 6, 367–372, November–December, 1999. 相似文献
4.
Synthesis,characterization and catalytic activities of bimetallic modified MCM-41 for epoxidation of styrene 总被引:1,自引:0,他引:1
Yuran Wang Yajie Guo Guangjian Wang Yiwu Liu Fei Wang 《Journal of Sol-Gel Science and Technology》2011,57(2):185-192
Mesoporous molecular sieves MCM-41 modified by bimetal (Zr and Ti) ions with ordered hexagonal arrangement were prepared by
direct synthesis under microwave–hydrothermal conditions at 403 K. FT-IR, N2 adsorption–desorption, scanning electron microscope, high-resolution transmission electron microscope, element mapping, X-ray
photoelectron spectroscopy, diffuse Reflectance UV–Visible Spectra etc. were used to characterize as-prepared materials. The
results showed that Zr and Ti were introduced into MCM-41 and bonds of Zr–O–Si and Ti–O–Si were formed in framework of the
MCM-41. Moreover, their structures with ordered arrangement were still retained. The microwave–hydrothermal method might shorten
the synthesis time from days to hours and the as-prepared catalyst had a high catalytic activity and selectivity for the liquid-phase
epoxidation of styrene. 相似文献
5.
I. I. Chernobaev M. N. Yakubovich A. I. Tripol’skií N. V. Pavlenko V. L. Struzhko 《Theoretical and Experimental Chemistry》1997,33(1):38-40
Methane is formed in the Fischer-Tropsch synthesis under real conditions both through intermediates leading to chain propagation
and by hydrogenation of surface carbon.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Prospekt Nauki 31, 252039 Kiev,
Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, No. 1, pp. 41–43, January–February, 1996. 相似文献
6.
The quantitative incorporation and high dispersion of platinum nanoparticles into MCM-41 has been carried out by the coordination
between Pt(IV) ion and APTMS-anchored MCM-41. Before and after calcination of Pt/APTMS/MCM41 samples, the Pt content in samples
was evaluated from home-made photoacoustic spectrometer (PAS). The PAS bands at 350 nm and 450 nm can be assigned to d–d transition bands of Pt complexes. By increasing the concentration of Pt solution, the PAS intensity of Pt/APTMS/MCM41 was
increased proportionally up to 1.0×10−2 M, and remained constant above 1.0×10−2 M. It can be attributed to the saturation of Pt content within Pt/APTMS/MCM41. The Pt content in the saturated Pt/APTMS/MCM41
was 8.5 wt% (the theoretical value), 9.7 wt% (measured by EDX) and 9.2 wt% (measured by ESCA), respectively. This indicates
that the content of Pt precursor within MCM-41 could be controlled by the concentration of Pt precursor solution. The PAS
intensity of calcined Pt/APTMS/MCM41's in H2 flow was increased up to 1.0×10−2 M and remained nearly constant above 1.0×10−2 M. Therefore, we suggest that the formation of Pt complexes with APTMS-anchored MCM-41 made it possible to incorporate quantitatively
Pt nanoparticles in the range of 0.5–9.2 wt% within MCM-41 channels. 相似文献
7.
A. S. Kovalenko A. S. Korchev V. G. Il'in A. P. Filippov 《Theoretical and Experimental Chemistry》1999,35(3):167-171
Mesoporous MSM-41 titanium silicate molecular sieves with high titanium content were synthesized. The hexagonal structure
along with high specific surface and pore volume are retained up to Si/Ti≥5.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039,
Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 3, pp. 177–182, May–June, 1999. 相似文献
8.
Luiz K. C. de Souza Juliana J. R. Pardauil José R. Zamian Geraldo N. da Rocha Filho Carlos E. F. da Costa 《Journal of Thermal Analysis and Calorimetry》2011,106(2):355-361
Al-modified MCM-41, La-modified MCM-41, and Ce-modified MCM-41 mesoporous materials were prepared with different molar ratios
(Si/M = 10; 25; 50; 100 and 200) at room temperature. The materials were characterized using XRD, BET–BJH, and TG–DTA. The
XRD showed four peaks, due to the ordered hexagonal array of parallel silica tubes, which could be indexed as (100), (110),
(200), and (210), assuming a hexagonal unit cell. The surface area decreased as the concentration of the metal incorporated
in the material increased. The thermal stability of the materials was around 650 °C. The CeO2 phase made the mass transfer process more difficult, hindering Hofmann degradation and favoring oxidation. 相似文献
9.
Pablo C. Schulz Marcela A. Morini Miriam Palomeque Jorge E. Puig 《Colloid and polymer science》2002,280(4):322-327
A novel procedure to synthesise V-doped surfactant–templated mesoporous materials in one step using a V(V) complex is described.
The resulting V(V)–MCM-41 material had a bimodal pore size distribution.
Received: 25 April 2001 Accepted: 20 June 2001 相似文献
10.
Jianmin Zhou Yulin Yang Lan Zhao Xiaokun Li Renxian Zhou Xiaoming Zheng 《Frontiers of Chemistry in China》2009,4(2):142-148
Using MCM-41 as the supporter, a series of MCM-41 supported amino-palladium complexes has been prepared and characterized
by XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy), etc. The XRD and XPS results indicate that the Pd coordinates
with the -NH2 groups on the MCM-41 surface, and the structure of MCM-41 has been not damaged. Its catalytic performance for Heck arylation
of alkene with aryl iodide shows that the catalysts have high activity and stereoselectivity in 70–90°C. The product of Heck
reaction is in E form. And the effect of the preparation condition of catalyst on the catalytic performance was examined.
Translated form Chinese Journal of Organic Chemistry, 2008, 28(5) (in Chinese) 相似文献
11.
S. V. Kolotilov K. S. Gavrilenko M. R. Kantserova A. V. Yakovenko N. N. Stepanenko N. V. Kas’yan A. V. Shvets 《Theoretical and Experimental Chemistry》2005,41(6):347-351
The effect of the composition of nanosized catalysts, produced by thermal decomposition of Co(II) and Cu(II) formates deposited
on ZrO2, SBA-15, and MCM-41, on their activity in the deep oxidation of methane was investigated. It was shown that the activity
of the catalyst depends on the nature of the support and on the Co/Cu ratio.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 41, No. 6, pp. 331–335, November–December, 2005. 相似文献
12.
Yu. G. Gol'tsov G. A. Puchkovskaya L. A. Matkovskaya I. I. Gnatyuk M. Markhevka 《Theoretical and Experimental Chemistry》2000,36(4):236-240
The proportions of the various states are determined by the cation composition of the matrix for liquid-crystal material encapsulated
in the pore spaces of mesoporous molecular sieves of MCM-41 type having high aluminum contents. The liquid-crystal properties
are retained in the encapsulated state.
Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 4, pp. 257–262, July–August, 2000. 相似文献
13.
Adsorption of CO2 was investigated over a wide range of conditions on a series of mesoporous silica adsorbents comprised of conventional MCM-41,
pore-expanded MCM-41 silica (PE-MCM-41) and triamine surface-modified PE-MCM-41 (TRI-PE-MCM-41). The isosteric heat of adsorption,
calculated from adsorption isotherms at different temperatures (298–328 K), showed a significant increase in CO2–adsorbent interaction after amine functionnalization of PE-MCM-41, consistent with the high CO2 uptake in the very low range of CO2 concentration. The CO2 adsorption isotherm and kinetics data showed the high potential of TRI-PE-MCM-41 material for CO2 removal in gas purification and separation applications. With TRI-PE-MCM-41, the CO2 selectivity over N2 was drastically improved over a wide range of conditions compared to pure mesoporous silica. Moreover, the adsorption was
reversible and fast, and the adsorbent was thermally stable and tolerant to moisture. 相似文献
14.
N. He C. Yang Q. Dai J. Wang C. Yuan Z. Lu 《Journal of Thermal Analysis and Calorimetry》2000,61(3):827-837
Siliceous MCM-41 mesoporous materials and those possessing Fe, La, Al,respectively, were synthesized using water glass as
silica source. Results from thermogravimetric analysis and other techniques showed us that Fe(III) or La(III) species was
incorporated into framework. Owing to Fe–O or La–O bond longer than Si–O bond, Fe(III) or La(III) species was limited to insert
into framework and transformed from tetrahedrally coordinated state to octahedrally coordinated state upon calcination to
remove template.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
S. V. Kolotilov A. V. Shvets N. V. Kas’yan 《Theoretical and Experimental Chemistry》2006,42(5):271-276
It was shown that the sorptive capacity for hydrogen in composites based on MCM-41 molecular sieves and nanoparticles of the
oxides of 3d metals or the metals themselves at 77 K and 1 atm is determined both by the surface area and by the volume of
the micropores of the samples and does not depend on the nature of the 3d metal (Ni, Co, Cu) or its degree of oxidation.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 5, pp. 265–270, September–October, 2006. 相似文献
16.
Coasne B Galarneau A Di Renzo F Pellenq RJ 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):11097-11105
This paper reports a molecular simulation and experimental study on the adsorption and condensation of simple fluids in mesoporous micelle-templated silicas MCM-41, MCM-48, and SBA-15. MCM-41 is described as a regular cylindrical silica nanopore, while SBA-15 is assumed to be made up of cylindrical nanopores that are connected through lateral channels. The 3D-connected topology of MCM-48 is described using a gyroid periodic minimal surface. Argon adsorption at 77 K is calculated for the three materials using Grand Canonical Monte Carlo simulations. Qualitative comparison with experiments for nitrogen adsorption in mesoporous micelle-templated silicas is made. The adsorption isotherm for SBA-15 resembles that for MCM-41. In particular, capillary condensation and evaporation are not affected by the presence of the connecting lateral channels. In contrast, the argon adsorption isotherm for MCM-48 departs from that for MCM-41 having the same pore size. While condensation in MCM-41 is a one-step process, filling of MCM-48 involves two successive jumps in the adsorbed amounts which correspond to condensation in different domains of the porosity. The condensation pressure for MCM-48 is larger than that for MCM-41. We attribute this result to the morphology of the MCM-48 surface (made up of both concave and convex regions) that differs from that for MCM-41 (concave only). Our results suggest that the pore connectivity affects pore filling when the size of the connections is comparable to that of the nanopores. 相似文献
17.
Gnatyuk I. I. Puchkovskaya G. A. Goltsov Yu. G. Matkovskaya L. A. Drozd M. 《Journal of Thermal Analysis and Calorimetry》2000,62(2):365-371
The results of nematic liquid crystal - isotropic liquid phase transition study by the method of differential scanning calorimetry
for inclusion compounds - mesoporous aluminosilicate molecular sieves of MCM-41 type (including Cu-exchanged samples) with
encapsulated in inner-crystalline space nematic liquid crystal (5CB), as well as IR spectroscopic data for such compounds
were represented. It was shown, that the 5CB molecules are able to interact with the active centers in the MCM-41 channels
forming strong enough bonds of -C≡N⋅⋅⋅H-O- type. The relative amount of 5CB molecules interacting with the walls of channels
and those retaining ‘liquid crystalline’ state in binary systems of molecular sieves MCM-41 and CuMCM-41 was estimated. This
conclusion was confirmed by the data obtained from differential scanning calorimetry measurements.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Yang Y Lim S Du G Wang C Ciuparu D Chen Y Haller GL 《The journal of physical chemistry. B》2006,110(12):5927-5935
The effect of initial synthesis solution pH and tetramethylammonium silicate concentration in the synthesis solution on the physical and chemical properties of MCM-41 was systematically investigated using N(2) physisorption, X-ray diffraction, temperature-programmed reduction, in situ Fourier transform IR, UV-vis, and X-ray absorption spectroscopies. pH and tetramethylammonium (TMA) fraction affect the porosity of MCM-41 and the reducibility of incorporated Ni cations; higher pH and TMA concentration produced more porosity with higher stability against reduction, which is attributed to more metal ions locating in the interior of the silica walls. The control of the pore diameter of mesoporous MCM-41 at the sub-nanometer scale may be accomplished by adjusting the pH and TMA fraction. pH may be used to control the surface free silanol group density and nickel reduction degree as well, and this is useful in the design of a specific catalyst for particular reactions, such as CO methanation, which requires highly dispersed, stable metallic clusters with controllable size. 相似文献
19.
In this work, batch adsorption experiments are carried out for crystal violet dye using mesoporous MCM-41 synthesized at room
temperature and sulfate modified MCM-41 prepared by impregnation method using H2SO4 as sulfatising agent. The surface characteristics, pore structure, bonding behavior and thermal degradation of both the MCM-41
samples are characterized by nitrogen adsorption/desorption isotherms, X-ray diffraction (XRD) patterns, Fourier transform
infrared (FT-IR) spectroscopy and thermo gravimetric analysis (TGA). The adsorption isotherm, kinetics and thermodynamic parameters
are investigated for crystal violet (CV) dye using the calcined and sulfated MCM-41. Results are analysed using Langmuir,
Freundlich and Redlich-Peterson isotherm models. It is found that the Freundlich model is an appropriate model to explain
the adsorption isotherm. The highest adsorption capacity achieved is found to be 3.4×10−4 mol g−1 for the sulfated MCM-41. The percentage removal of crystal violet dye increases with increase in the pH for both the MCM-41
adsorbents. Kinetics of adsorption is found to follow the second-order rate equation. From the thermodynamic investigation,
it is evident that the adsorption is exothermic in nature. 相似文献
20.
S. Ya. Kuchmii B. F. Minaev A. V. Korzhak A. I. Kryukov 《Theoretical and Experimental Chemistry》1997,33(1):16-20
A mechanism of photocatalytic synthesis of chlorohydrins from olefins and peroxo complexes of titanium (IV) is proposed. It
consists of formation of radical-containing complexes, their reactions with olefins, and decomposition of the α-oxides obtained
by hydrogen chlorides.
L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prosp. Nauki, 252039 Kiev,
Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 1, pp. 17–21, January–February, 1997. 相似文献