Synthesis of Nanoporous Materials Al-MCM-41 from Natural Halloysite

NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550005 ◽  
Author(s):  
Yaling Xie ◽  
Aidong Tang ◽  
Huaming Yang
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Halloysite Nanotubes ◽  
Nanoporous Materials ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Naoh Solution ◽  
The One ◽  
Mcm 41

Nanoporous materials Al -MCM-41 with varying Si / Al molar ratios have been successfully synthesized from natural clay mineral halloysite nanotubes (HNTs). Hydrothermal treatment of acid-pretreated HNTs and NaOH solution resulted in the one-step synthesis of final nanoporous products by using surfactant. The effects of Si / Al molar ratios (7.7, 61.0 and 176.5) on the surface area, porosity and degree of structural order of Al -MCM-41 materials have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption–desorption measurements and Fourier transform infrared (FTIR) spectra techniques. The results indicated that Si / Al molar ratio had important effect on the characteristics of nanoporous materials, and Al -MCM-41 with an intermediate Si / Al molar ratio of 61.0 exhibited excellent characteristics with high degree of order, high surface area (S BET ) of 1033 m2/g and pore volume of 0.92 mL/g.

scholarly journals Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active ◽  
Ultrasonic Assisted ◽  
Sulfur Capacity ◽  
Mcm 41

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

One-pot aerobic oxidative sulfonamidation of aromatic thiols with ammonia by a dual-functional β-MnO2 nanocatalyst

2020 ◽  
Vol 56 (14) ◽  
pp. 2095-2098 ◽  
Author(s):  
Eri Hayashi ◽  
Yui Yamaguchi ◽  
Yusuke Kita ◽  
Keigo Kamata ◽  
Michikazu Hara
Keyword(s):  
High Activity ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
One Pot ◽  
Dual Functional ◽  
Aromatic Thiols ◽  
The One

High-surface-area β-MnO2 nanoparticles exhibited high activity for the one-pot oxidative sulfonamidation of thiols to sulfonamides using O2 and NH3.

Adsorption of different dyes from aqueous solution using Si-MCM-41 having very high surface area

2016 ◽  
Vol 23 (5) ◽  
pp. 1227-1237 ◽  
Author(s):  
Haribandhu Chaudhuri ◽  
Subhajit Dash ◽  
Ashis Sarkar
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Very High ◽  
Mcm 41

scholarly journals Synthesis and characterization of porous silica and polyaniline-porous silica composite materials with high surface area

2014 ◽  
Vol 49 (1) ◽  
pp. 1-8
Author(s):  
US Akhtar ◽  
MK Hossain ◽  
MS Miran ◽  
MYA Mollah
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
Nitrogen Adsorption ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Cylindrical Pore

Porous silica materials were synthesized from tetraethyl orthosilicate (TEOS) using Pluronic P123 (non-ionic triblock copolymer, EO20PO70O20) as template under acidic conditions which was then used to prepare polyaniline (PAni) and porous silica composites (PAnisilica) at a fixed molar ratio. These materials were characterized by nitrogen adsorption-desorption isotherm measured by Barrett-Joyner- Halenda (BJH) method and pore size distribution from desorption branch and surface area measured by the Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), TEM-energy dispersive X-ray (EDX) and Fourier transform infrared (FT-IR) spectroscopy. The composite maintains its structure even after the polymerization and the polymer is dispersed on the inorganic matrix. The rod-like porous silica was about 1?m to 1.5 ?m long and on an average the diameter was in the range of 300- 500 nm. The SEM and TEM images show well ordered 2d hexagonal pore, high specific surface area (850 m2g-1) and uniform pore size of ca. 6.5 nm in diameter. After incorporation of PAni inside the silica pore, framework of porous silica did not collapse and the surface area of the composite was as high as 434 m2g-1 which was 5.5 time higher than our previous report of 78.3 m2g-1. Due to shrinkage of the framework during the incorporation of aniline inside the silica, the pore diameter slightly increase to 7.5 nm but still showing Type IV isotherm and typical hysteresis loop H1 implying a uniform cylindrical pore geometry. DOI: http://dx.doi.org/10.3329/bjsir.v49i1.18847 Bangladesh J. Sci. Ind. Res. 49(1), 1-8, 2014

Nanostructured Ni/CeO2–ZrO2 Catalysts for CO2 Conversion into Synthetic Natural Gas

2019 ◽  
Vol 19 (6) ◽  
pp. 3269-3276 ◽  
Author(s):  
Luciano Atzori ◽  
Elisabetta Rombi ◽  
Daniela Meloni ◽  
Roberto Monaci ◽  
Maria Franca Sini ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
High Surface ◽  
High Surface Area ◽  
Xrd Analysis ◽  
Molar Ratio ◽  
Soft Template ◽  
Synthetic Natural Gas ◽  
Molar Ratios ◽  
Mild Reduction ◽  
Average Size

NiO–CeO2–ZrO2 mixed oxides, with Ni/(Ce + Zr) = 1 mol/mol and different Ce/Zr molar ratios, were prepared by the soft-template method. The chemical composition, texture, structure, and redox features of the synthesized systems were investigated by different techniques. All samples were nanocrystalline (NiO nanocrystal average size 4 nm) and had high surface area and quite an ordered mesoporous system. The catalytic performances in the CO2 conversion into methane were studied at atmospheric pressure, 300 °C, and stoichiometric H2/CO2 molar ratio. Prior to reaction the catalysts were submitted to a mild reduction pretreatment (H2 at 400 °C for 1 h). XRD analysis of the samples after pretreatment showed the presence of small Ni crystals (4–7 nm) on all the samples as well as of some unreduced NiO nanocrystals on the systems with high Zr content, in accordance with H2-TPR experiments, which indicated that NiO reduction is promoted by CeO2 but hindered by ZrO2. The catalytic tests were performed at two different space velocities (72000 and 900000 cm3 h−1 g−1cat) on a series of Ni-based catalysts supported on CeO2–ZrO2 systems with different Ce/Zr ratios, including the two pure oxides. CO2 conversion and selectivity to CH4 (which was always close to 100 mol%) were constant throughout the 6-hour runs. CO2 conversion resulted to increase with CeO2 content in the catalyst, thus indicating the role of the CeO2 component of the support in activating CO2, whereas H2 is activated on the Ni nanoparticles.

Supercritical flow synthesis of PtPdFe alloyed nanoparticles with enhanced low-temperature activity and thermal stability for propene oxidation under lean exhaust gas conditions

2019 ◽  
Vol 9 (23) ◽  
pp. 6691-6699
Author(s):  
Hugo Silva ◽  
Patricia Hernandez-Fernandez ◽  
Ane K. Baden ◽  
Henrik L. Hellstern ◽  
Anton Kovyakh ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Exhaust Gas ◽  
Propene Oxidation ◽  
Supercritical Flow ◽  
One Step ◽  
The One

Supercritical flow technology was used for the one step production of PtPd and PtPdFe nanoparticles supported on high surface area γ-Al2O3.

Template-Method Synthesis of High-Surface-Area Monolithic Carbon Aerogels and Their Applications for Hydrogen and Deuterium Adsorption

2017 ◽  
Vol 16 (05n06) ◽  
pp. 1750010 ◽  
Author(s):  
Bowei Chen ◽  
Xiaojun Wang ◽  
Jiayi Zhu ◽  
Yutie Bi ◽  
Xuan Luo ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Hydrogen Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
Carbon Aerogel ◽  
Molar Ratio ◽  
Template Method ◽  
Carbon Aerogels ◽  
Polymer Templates

In this work, novel monolithic carbon aerogels obtained by using a polymer template method were characterized and evaluated for their applications in the hydrogen and deuterium adsorption capacity. The properties (i.e., surface area, pore size distribution, hydrogen and deuterium adsorption capacities, etc.) of the carbon aerogels were affected by the polymer templates. The results showed that the carbon aerogel with the molar ratio of polyacrylic acid (PAA) to zinc chloride (ZnCl2) being 0.75:40 was featured the highest surface area (1806 m2/g) and had the highest hydrogen adsorption capacity. Moreover, the deuterium adsorption capacity of the carbon aerogel was to be further elucidated.

One-Step Hydrothermal Synthesis of MoS2 Nano-Flowers with High Surface Area and Crystalline

2012 ◽  
Vol 531-532 ◽  
pp. 508-511 ◽  
Author(s):  
Yan Juan Li ◽  
Nan Li ◽  
Xiao Yan ◽  
Yue Chi ◽  
Qing Yuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Surface Area ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Ammonium Molybdate ◽  
Molar Ratio ◽  
Sulfur Source ◽  
One Step

One-step and controlled pH hydrothermal synthesis of transition metal disulfide using double molybdenum sources to synthesize MoS2 nano-flowers at low temperature was first reported. Anhydrous molybdenum pentachloride (MoCl5) and four sulfur ammonium molybdate ((NH4) 6Mo7O24•4H2O) were the molybdenum source and CS (NH2) 2 was the sulfur source. Through hydrothermal method, MoS2 was obtained at 180 °C. The pH value of system was controlled by adjusting the molar ratio of MoCl5 and (NH4) 6Mo7O24•4H2O. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area (BET) and transmission electron microscopy (TEM). The results show that the products were hexagonal MoS2 with a high crystalline and flower-like structure consisted of small particles. The thickness of petals is a few to tens of nanometers. By changing the molar ratio of molybdenum sources, the resultant phase from the mixed phase transited to the pure phase and the purity of synthetic MoS2 crystal increaseed.

The Application of Sepiolite in Aluminium Silicate Fiber Paper

2012 ◽  
Vol 550-553 ◽  
pp. 3347-3351
Author(s):  
Sha Wang ◽  
Chuan Shan Zhao ◽  
Dai Qi Wang ◽  
Wen Jia Han
Keyword(s):  
Tensile Strength ◽  
Surface Area ◽  
Smooth Surface ◽  
High Surface ◽  
High Surface Area ◽  
Mass Ratio ◽  
The One ◽  
Aluminium Silicate

Sepiolite has good adsorptivity due to their high surface area and structural channels. During the process of making aluminium silicate fiber paper, inorganic binders retaintion was little because of the smooth surface of aluminium silicate fibers. In this study, sepiolite was used to improve tensile strength of the sheet by increasing inorganic binders retaintion rate through its high adsorptivity. The effect of sepiolite on the tensile strength of alimunium silicate fiber paper was investigated. The results showed that the best mass ratio of aluminium silicate fibers to spiolite was 7:3. Under this condition, the tensile strength of the sheet was 4.79 N•m/g, which increased by 24.2% from the one without sepiolite.

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