scholarly journals Hierarchical ZSM-5 Zeolite with Enhanced Catalytic Activity for Alkylation of Phenol with Tert-Butanol

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 202 ◽  
Author(s):  
Ling Xu ◽  
Fan Wang ◽  
Zhiqiang Feng ◽  
Zongrui Liu ◽  
Jingqi Guan
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Structure ◽  
Soft Template ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Tert Butanol ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Phenol Conversion

Using polyethylene glycol as a mesoporous soft template, a series of hierarchically porous ZSM-5 zeolites were prepared. X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, and transmission electron microscopy results demonstrated that the resultant materials contained a micro–mesoporous structure. Since the existence of mesoporous structure favors the diffusion of large molecular reactants and products, the phenol conversion and selectivity to 2,4-Di-TBP on the hierarchical ZSM-5 zeolite can be improved for the alkylation of phenol with tert-butanol.

Comparison of TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 Hybrid Catalysts in Characteristics and Photodegradation of Tetramethylammonium

2010 ◽  
Vol 93-94 ◽  
pp. 22-26 ◽  
Author(s):  
Surachai Artkla ◽  
Won Yong Choi ◽  
Jatuporn Wittayakun
Keyword(s):  
Irradiation Time ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Adsorption Desorption ◽  
Two Hybrid ◽  
Mcm 41

This work compared properties and catalytic performance of two hybrid photocatalysts, TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 prepared by loading nanoparticles of TiO2 (10 wt.%) on MCM-41 synthesized with rice husk silica and tetraethyl orthosilicate respectively. The supports and catalysts were characterized by X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy and zeta potential. The photocatalytic activities of the TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 for the degradation of tetramethylammonium (TMA) in aqueous slurry were similar with a complete conversion after irradiation time of 90 min at pH 7.

Ordered Mesoporous SBA-15 for Controlled Release of Water-Insolube Drug

2011 ◽  
Vol 236-238 ◽  
pp. 1873-1876 ◽  
Author(s):  
Jun Jie Tao ◽  
Yun Qiang Xu ◽  
Guo Wei Zhou ◽  
Cui Cui Wu ◽  
Hong Bin Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Controlled Release ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Mesoscopic Structure ◽  
Ordered Mesoporous ◽  
Adsorption Desorption ◽  
Phosphate Buffered Saline

Ordered mesoporous SBA-15 was synthesized through hydrothermal process under acidic condition. The material was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), and N2 adsorption-desorption. The results indicated that SBA-15 has 2-dimensional hexagonal p6mm mesoscopic structure and well-ordered parallel mesochannel. The as-obtained mesoporous silica was used for controlled release of water-insolube drug emodin. The loading capacity could achieve 6.64 mg/g, and the release profiles that studied in phosphate buffered saline (PBS, pH = 7.4) showed that released amount of emodin was 95.8 % after 48 h.

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.

Preparation and Characterization of Vanadium Pentoxide Hollow Microspheres with Tunable Sizes

2016 ◽  
Vol 697 ◽  
pp. 706-709
Author(s):  
Ming Gong ◽  
Chang An Wang
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Method ◽  
Hollow Microspheres ◽  
Soft Template ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Weights ◽  
Transmission Electron ◽  
One Step

V2O5 hollow microspheres were synthesized by a one-step solvothermal method, with the assistance of PVP as the soft template, ethylene glycol (EG) as the solvent, and vanadium (iii) acetylacetonate (acac) as the metal-ions source. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM). The size of V2O5 hollow microspheres, which can be easily tuned by using PVP of different molecular weights, was about 2.5μm, 4.5μm and 6μm when using PVP-K17, PVP-K30 and PVP-K60 as the template, respectively.

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 of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

scholarly journals Novel Route to Obtain Carbon Self-Doped TiO2 Mesoporous Nanoparticles as Efficient Photocatalysts for Environmental Remediation Processes under Visible Light

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3349 ◽  
Author(s):  
Pablo A. Ochoa Rodríguez ◽  
Tamara B. Benzaquén ◽  
Gina A. Pecchi ◽  
Sandra G. Casuscelli ◽  
Verónica R. Elías ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Synthesis Method ◽  
Mesoporous Structure ◽  
Acid Orange 7 ◽  
X Ray Diffraction ◽  
Visible Radiation ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.

Synthesis and Characterization of Nanocrystalline CeO2

2006 ◽  
Vol 306-308 ◽  
pp. 1103-1108
Author(s):  
Abdul Hadi ◽  
Iskandar Idris Yaacob
Keyword(s):  
Fine Particles ◽  
Gas Adsorption ◽  
Mesoporous Structure ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered ◽  
Adsorption Desorption

Nanocrystalline CeO2 has been synthesized at room temperature using water-in-oil (w/o) microemulsion technique. The structure and properties of the nanocrystalline CeO2 were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and gas adsorption desorption measurement. XRD results showed the synthesized CeO2 has a face centered cubic structure with crystallite size of about 5.2 nm. TEM observation also indicated the presence of nanometer sized particles of CeO2. Coarser particles were also observed due to agglomeration. Gas adsorption desorption isotherms showed the behavior of fine particles with mesoporous structure.

scholarly journals Photocatalytic Reduction of CO2Using TiO2-Graphene Nanocomposites

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Jinghua Liu ◽  
Yinghua Niu ◽  
Xiong He ◽  
Jingyao Qi ◽  
Xin Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Adsorption Desorption

TiO2-graphene (TiO2-RGO) nanocomposites were preparedviaa simple chemical method by using graphene oxide (GO) and TiO2nanoparticles as starting materials. The morphologies and structural properties of the as-prepared composites were characterized by X-ray diffraction, Raman spectroscopy, N2adsorption-desorption measurements, and transmission electron microscopy. TiO2-RGO nanocomposites exhibited great photocatalytic activity toward reduction of CO2into CH4(2.10 μmol g−1 h−1) and CH3OH (2.20 μmol g−1 h−1), which is attributed to the synergistic effect between TiO2and graphene.

Mesoporous TiO2 Prepared by Using Lac Red as Template：Synthesis, Characterization, and Adsorption of Gaseous Acetaldehyde

2013 ◽  
Vol 742 ◽  
pp. 448-451
Author(s):  
Ming Feng Wang ◽  
Tou Gen Liao ◽  
Bao Kun Zhu ◽  
Yao Wang ◽  
Yan Qing Duan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mesoporous Titania ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Scanning Electron

Mesoporous TiO2 with anatase crystalline structure (MTiO2) has been synthesized by using Lac Red as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption. It was found that without any external doping MTiO2 exhibited significant high adsorption abilities for adsorbing the gaseous acetaldehyde by the adsorption ratio of 39.15%.

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