Preparation and Characterization of MCM-41 Mesoporous Silica Functionalized with Sulfonic Acid Groups

2013 ◽  
Vol 781-784 ◽  
pp. 215-218
Author(s):  
Xue Ding ◽  
Xi Chang Yu ◽  
Hai Xia Sun
Keyword(s):  
Molecular Sieve ◽  
Sulfonic Acid ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
X Ray Diffraction ◽  
Sh Group ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Sulfonic Acid Groups ◽  
Mcm 41

Mesoporous molecular sieve MCM-41 was modified by using 3-mercaptopropyltriethoxysilane as a coupling agent and MCM-41 functionalized with sulfonic acid groups was prepared. The prepared product was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption technique and temperature programmed desorption. The results showed that during the process of modification the frameworks of the molecular sieve were not destroyed, the channel has ordered property. SH group was successfully grafted to the surface of channels of the molecular sieve. The acid amount on the mesoporous material functionalized with sulfonic acid groups reached 0.755mmol/g, showing a potential application foreground as a catalyst.

Synthesis and Characterization of Mesoporous Molecular Sieve Al-MCM-41 Using Kaolin as Raw Material

2013 ◽  
Vol 779-780 ◽  
pp. 201-204
Author(s):  
Miao Li ◽  
Hong Wang ◽  
Xian Qing Li ◽  
Jin Rong Liu
Keyword(s):  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Calcined Kaolin ◽  
Mcm 41

Ordered hexagonally mesoporous molecular sieve Al-MCM-41 with Si/Al (atom) ratio=9 was prepared by hydrothermal synthesis using raw kaolin. X-ray diffraction (XRD), Nitrogen adsorption desorption, Transmission Electron Microscope (TEM) and Energy Dispersive X-ray Detector (EDX) were employed to characterise raw kaolin, calcined kaolin, as-synthesized and calcined Al-MCM-41. The results indicated that characteristic reflections of raw kaolin disappeared after calcination, both of as-synthesized and calcined Al-MCM-41 exhibited well ordered hexagonally mesoporous molecular sieve structure.

Design of composite micro/mesoporous molecular sieve catalysts

2004 ◽  
Vol 76 (9) ◽  
pp. 1647-1657 ◽  
Author(s):  
I. I. Ivanova ◽  
A. S. Kuznetsov ◽  
V. V. Yuschenko ◽  
E. E. Knyazeva
Keyword(s):  
Mesoporous Materials ◽  
Active Sites ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
Temperature Programmed ◽  
Angle Spinning ◽  
Adsorption Desorption

Two series of composite micro/mesoporous materials with different contributions of micro- and mesoporosity were prepared by dealumination and recrystallization of mordenite zeolite. The materials were characterized by X-ray diffraction, infrared spectroscopy, 27Al magic angle spinning (MAS) NMR, nitrogen adsorption–desorption, and temperature-programmed desorption of ammonia (TPD NH3). Catalytic properties were studied in transalkylation of biphenyl with diisopropylbenzene. Both types of composite materials showed remarkably high activity, stability, and selectivity toward formation of di-isopropylbiphenyls with respect to both pure microporous and mesoporous materials. The effect is due to high zeolitic acidity combined with improved accessibility of active sites and transport of bulky molecules provided by mesopores.

scholarly journals Manufacture Porous Materials by Dabco-Based Lonic Liquid

2021 ◽  
Author(s):  
Haleh Sanaeishoar ◽  
Maryam Sabbaghan ◽  
Sahar Peimanfar
Keyword(s):  
Surface Area ◽  
Molecular Sieve ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Molecular Sieve ◽  
X Ray Diffraction ◽  
Easy Method ◽  
Hexagonally Ordered ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract The long-chain ionic liquid (IL) hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide was used as a template to prepare the hexagonally ordered siliceous mesoporous molecular sieve MCM-41 as well as the disordered mesoporous molecular sieve designated as KIT-1. The synthesized products were studied via X-ray diffraction (XRD), Fourier transform infrared (FTIR) and N2 adsorption-desorption analysis. The surface area (BET), pore volume, and pore diameter (BJH) are determined. These kind of ILs that have DABCO (1,4-diazabicyclo[2.2.2]octane) in their structures, were prepared with an easy method. When the two templates, cetyltrimethylammonium bromide (CTAB) and IL, have the similar structures, MCM-41 mesoporous molecular sieve produced with more ordered, uniform mesoporous channel and high surface area in comparison to without IL. When just IL used instead of CTAB, the KIT-1 with non-uniform mesoporous was obtained. Here we prepared the KIT-1 mesoporous molecular sieve with IL without CTAB but it seems, using dual template with changing IL structures in fabricated of molecular sieve provide new opportunity to design targeted adsorbents and catalysis.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

Effect of Synthesis Duration on the Physicochemical Properties of Siliceous Mesoporous Molecular Sieve (Si-MMS)

2012 ◽  
Vol 326-328 ◽  
pp. 647-653 ◽  
Author(s):  
Anita Ramli ◽  
Sohail Ahmed ◽  
Suzana Yusup
Keyword(s):  
Physicochemical Properties ◽  
Pore Structure ◽  
Molecular Sieve ◽  
Mesoporous Material ◽  
Mesoporous Molecular Sieve ◽  
Diffraction Peaks ◽  
Adsorption Desorption ◽  
Synthesized Materials ◽  
Synthesis Duration ◽  
Mcm 41

Pure silica mesoporous molecular sieve (MMS) solid has been synthesized at 100°C by hydrothermal process. The effect of synthesis duration from 2 to 10 days has been investigated on the physicochemical properties of mesoporous molecular sieve. Samples were characterized by low angle XRD, N2adsorption-desorption and HRTEM analysis. XRD patterns of the as-synthesized samples showed four well-defined diffraction peaks corresponding to 100, 110, 200 and 210 planes. These peaks are the fingerprint characteristics of MCM-41 mesoporous material. The high intensity diffraction peaks were observed in 8-days sample that define the high ordering of the pores and long range order. N2adsorption-desorption results showed that all samples possessed a type IV isotherm having hysteresis loop of typeH1which is an identification of mesoporous material. Calcined samples exhibited high surface area i.e., 984-1036 m2g-1, pore volume i.e., 1.00-1.13 cm3g-1and average pore diameter i.e., 3.04-3.30 nm. A hexagonal pore structure was found in the synthesized materials by HRTEM analysis, which confirms that the synthesized materials are MCM-41. HRTEM analysis showed the effect of synthesis duration on the materials and found that 8-days sample exhibited highly ordered hexagonal pore structure like honeycomb structure. All the samples were calcined at 550°C to remove the template and to study the changes in the mesoporous framework. The results showed that the mesoporous structure remained intact after calcination at 550°C, indicating that the mesoporous materials exhibit high thermal stability.

scholarly journals Heterogeneous Fenton-Like Catalytic Removal of Methylene Blue Dye in Water Using Magnetic Nanocomposite (MCM-41/Magnetite)

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
André E. Nogueira ◽  
Isabela A. Castro ◽  
Amanda S. Giroto ◽  
Zuy M. Magriotis
Keyword(s):  
Blue Dye ◽  
X Ray Diffraction ◽  
Active Systems ◽  
Toc Removal ◽  
Transmission Electron ◽  
Degradation Activity ◽  
Temperature Programmed ◽  
Catalytic Removal ◽  
Adsorption Desorption ◽  
Mcm 41

In this work, MCM-41, magnetite (MAG), and a composite of magnetite and MCM-41 (MCM-MAG) were synthesized by a simple route for the production of active systems in the decomposition of organic waste. The materials were characterized by N2 adsorption/desorption, X-ray diffraction analysis (XRD), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). Our results indicated that the decolorization kinetics of the dyes were in the order of MCM-MAG > MCM-41 > magnetite. Mineralization of the dyes was monitored by total organic carbon (TOC) decrease. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal 43% for a Fenton-like reaction time of 180 min. The degradation activity of the MCM-MAG was stable during four consecutive experiments, confirming their stability and reusability of the composite. The great advantage of this composite is that it may be easily magnetically recovered and reused.

Catalytic Activity of Argentum-loaded MCM-41 for Ozonation of p- Chlorobenzoic Acid (p-CBA) in Aqueous Solution

2015 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhaoqi Pan ◽  
Junyu Zeng ◽  
Bingyan Lan ◽  
Laisheng Li
Keyword(s):  
Aqueous Solution ◽  
Nitrogen Adsorption ◽  
Hexagonal Structure ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Chlorobenzoic Acid ◽  
Transmission Electron ◽  
Initial Ph ◽  
Adsorption Desorption ◽  
Mcm 41

AbstractArgentum-loaded MCM-41 (Ag/MCM-41) was synthesized successfully by a hydrothermal method and used as a catalyst for the ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution. Ag/MCM-41 was characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption and transmission electron microscopy (TEM). Characterizations suggest that the prepared samples retained a highly regulated mesopores of hexagonal structure and a high BET surface area. The influences of argentum content, initial pH, reaction temperature on the catalytic ozonation were also evaluated. Ag/MCM-41/O

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

Studies on (SBA-15)-AgI Host-Guest Nanocomposite Materials

2015 ◽  
Vol 723 ◽  
pp. 481-484
Author(s):  
Xiao Dong Li
Keyword(s):  
Molecular Sieve ◽  
Solid Phase ◽  
Nitrogen Adsorption ◽  
Nanocomposite Materials ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Radiation Process ◽  
Thermal Diffusion Method ◽  
New Type ◽  
Adsorption Desorption

SBA-15 molecular sieve owned the characteristic of uniform nanoscale channels, large pores, thick walls and high hydrothermal stability. It has the potential foreground as adsorption, separation, catalysis and new type host-guest nanocomposite materials. In this paper, SBA-15 molecular sieve was synthesized in acidic medium by hydrothermal method using triblock copolymers (EG20PG40EG20) as template, tetraethoxysilane as silica resource. Semiconductor material AgI was incorporated into the mesoporous channels of the SBA-15 molecular sieve by solid phase thermal diffusion method and the (SBA-15)-AgI nanocomposites materials were prepared. The products were characterized by means of powder X-ray diffraction, low-temperature nitrogen adsorption-desorption technique at 77 K and luminous properties were studied. The results showed that AgI went into the channels of the SBA-15, the materials (SBA-15)-AgI remained the highly ordered two-dimensional hexagonal. However, the crystalline was decreased to some degree, the pore volume, pore size and the surface area decreased to some extent compared to those of the SBA-15 molecular sieve. It was found by luminous studies that the energy band gap of the (SBA-15) -AgI composite material is very high and radiation process is very strong. The composite materials possess very good luminous performance and can be hopefully acted as luminous materials.

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

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