Sucrose-Template Synthesis of Mesoporous Alumina from Aqueous Systems

2010 ◽  
Vol 6 (2) ◽  
Author(s):  
Benjing Xu ◽  
Zifeng Yan ◽  
Yuxia Zhu ◽  
Huiping Tian ◽  
Jun Long
Keyword(s):  
Thermal Analyses ◽  
High Surface ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Aqueous System ◽  
Mesoporous Alumina ◽  
X Ray Diffraction ◽  
Excellent Thermal Stability ◽  
Transmission Electron ◽  
Adsorption Desorption

Mesoporous alumina was prepared by using sucrose as a structure-directing template in an aqueous system. The resultant samples were characterized by using different methods such as x-ray diffraction, transmission electron microscopy, nitrogen adsorption-desorption analysis, and thermogravimetric and differential thermal analyses. The results showed that the prepared mesoporous gamma alumina has high surface area, uniform pore size distribution and excellent thermal stability.

Synthesis and Characterization of ZrO2/Graphene Nanocomposite Materials

2012 ◽  
Vol 531 ◽  
pp. 161-164 ◽  
Author(s):  
Zong Hua Wang ◽  
Fu Qiang Zhu ◽  
Jan Fei Xia ◽  
Fei Fei Zhang ◽  
Yan Zhi Xia ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Transmission Electron ◽  
Ft Ir ◽  
Graphene Nanocomposite ◽  
Adsorption Desorption

Zirconia/graphene (ZrO2/graphene) nanocomposite has been successfully synthesized by a simple method. The as-prepared nanocomposite was characterized using transmission electron microscopy (TEM), FT-IR spectroscopy, power X-ray diffraction (XRD) and nitrogen adsorption-desorption. It was found that tetragonal ZrO2was uniformly deposited on graphene, which resulted in the formation of two-dimensional nanocomposite, it showed a high surface area of 165 m2/g.

Texture Evaluation of Sol-Gel Derived Mesoporous Bioactive Glass

2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih
Keyword(s):  
Surface Area ◽  
Calcination Temperature ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Bioactive Glasses ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Adsorption Desorption

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.

A Novel Structural Mesoporous Alumina/Yttrium Doped Zirconia Nanocrystalline Composite Derived by Solvothermal Approach

2005 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Hangrong Chen ◽  
Xin Michael Wang ◽  
Jianlin Shia ◽  
Ping Xiao ◽  
Dongsheng Yan
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Mesoporous Alumina ◽  
Infrared Transmission ◽  
Scanning Calorimetry ◽  
Uniform Size ◽  
Transmission Electron ◽  
Nanocrystalline Zirconia ◽  
Nanocrystalline Composite

A novel structural mesoporous alumina (40 mol%)/yttrium doped zirconia nanocrystalline composite has been synthesized by a solvothermal process using ethanol and ethylene glycol as a co-solvent. X-ray diffraction, thermogravimetry/differential scanning calorimetry, Fourier transform infrared, transmission electron microscopy, and nitrogen adsorption are used for the structural characterization. This novel mesoporous alumina/zirconia nanocomposite presents nanocrystalline zirconia particles with a uniform size less than 5 nm surrounded by alumina, forming a kind of core-shell structure after calcined at 800 °C. The mesostructural composite has high surface area (higher than 250 m2/g) and a narrow pore-size distribution of about 3.2 nm throughout the composite sample. The uniformly distributed nanocrystalline zirconia particles and the surrounding wormlike alumina framework act as the inorganic wall for the mesopores.

Positron Annihilation Study of Porous ZnO Synthesized with Soft Template

2017 ◽  
Vol 373 ◽  
pp. 299-302
Author(s):  
Bo Zhou ◽  
Chong Yang Li ◽  
Ning Qi ◽  
Zhi Quan Chen
Keyword(s):  
Pore Size ◽  
Positron Lifetime ◽  
Nitrogen Adsorption ◽  
Soft Template ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Long Lifetime ◽  
Positron Annihilation Study ◽  
Adsorption Desorption

Porous ZnO were synthesized with soft template method using zinc acetate Zn (CH3COO)2·2H2O as precursor and block copolymer F127 as the surfactant. Nitrogen adsorption-desorption measurements indicate that the ZnO sample contains large pores with mean diameter of about 30 nm. However, both small-angle X-ray diffraction and transmission electron microscope measurements indicate that the pore ordering is missing. Positron lifetime measurements reveal two long lifetime components in the porous ZnO. The longest lifetime τ4 (75 ns) corresponds to ortho-positronium (o-Ps) annihilation in large pores. The pore size estimated from τ4 is about 10.6 nm. This is much smaller than that estimated from Nitrogen adsorption-desorption measurements. In addition, the intensity I4 is only about 2.2%. This is probably due to the chemical quenching and/or inhibition of positronium formation induced by ZnO, which reduces o-Ps lifetime and intensity, and leads to under estimation of the pore size.

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

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.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

scholarly journals Synthesis and Characterization of Hierarchical Porousα-FeOOH for the Adsorption and Photodegradation of Rhodamine B

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jianliang Cao ◽  
Gaojie Li ◽  
Yan Wang ◽  
Guang Sun ◽  
Hari Bala ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rhodamine B ◽  
Uv Light ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Hierarchical Porous ◽  
Templated Method

Hierarchical porousα-FeOOH nanoparticles were controlled and prepared via a facile polystyrene (PS) microspheres-templated method. Theα-Fe2O3was obtained by the calcination of the as-preparedα-FeOOH. The resulting nanoparticles were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2-sorption techniques. The adsorption and photodegradation of Rhodamine B performance were evaluated under UV light at room temperature. The results indicated that the photocatalytic activity of theα-FeOOH nanoparticles is superior toα-Fe2O3-200 andα-Fe2O3-300 due to the hierarchically multiporous structure and high surface area. This convenient and low-cost process provides a rational synthesis alternative for the preparation of multiporous materials and the as-synthesis products have great foreground applications in many aspects.

scholarly journals Oxidative Coupling of Methane over Mn2O3-Na2WO4/SiC Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 363
Author(s):  
Jieun Kim ◽  
La-Hee Park ◽  
Jeong-Myeong Ha ◽  
Eun Duck Park
Keyword(s):  
Electron Microscopy ◽  
High Temperatures ◽  
Oxidative Coupling ◽  
Exothermic Reaction ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Oxidative Coupling Of Methane ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Adsorption Desorption

The oxidative coupling of methane (OCM) is operated at high temperatures and is a highly exothermic reaction; thus, hotspots form on the catalyst surface during reaction unless the produced heat is removed. It is crucial to control the heat formed because surface hotspots can degrade catalytic performance. Herein, we report the preparation of Mn2O3-Na2WO4/SiC catalysts using SiC, which has high thermal conductivity and good stability at high temperatures, and the catalyst was applied to the OCM. Two Mn2O3-Na2WO4/SiC catalysts were prepared by wet-impregnation on SiC supports having different particle sizes. For comparison, the Mn2O3-Na2WO4/SiO2 catalyst was also prepared by the same method. The catalysts were analyzed by nitrogen adsorption–desorption, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The transformation of SiC into α-cristobalite was observed for the Mn2O3-Na2WO4/SiC catalysts. Because SiC was completely converted into α-cristobalite for the nano-sized SiC-supported Mn2O3-Na2WO4 catalyst, the catalytic performance for the OCM reaction of Mn2O3-Na2WO4/n-SiC was similar to that of Mn2O3-Na2WO4/SiO2. However, only the surface layer of SiC was transformed into α-cristobalite for the micro-sized SiC (m-SiC) in Mn2O3-Na2WO4/m-SiC, resulting in a SiC@α-cristobalite core–shell structure. The Mn2O3-Na2WO4/m-SiC showed higher methane conversion and C2+ yield at 800 and 850 °C than Mn2O3-Na2WO4/SiO2.

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