Evidence for ordering of cobalt ions in the microporous solid acid catalyst CoDAF-4 by single crystal X-ray diffraction and resonant X-ray powder diffraction

2000 ◽  
Vol 2 (3) ◽  
pp. 407-412 ◽  
Author(s):  
P. A. Barrett ◽  
R. H. Jones
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
X Ray Diffraction ◽  
Cobalt Ions ◽  
X Ray

scholarly journals A SYNTHESIS OF SOLID ACID CATALYSTS FOR USING IN HYDROLYSIS OF CELLULOSE FROM RICE STRAW INTO GLUCOSE

2018 ◽  
Vol 55 (1B) ◽  
pp. 145
Author(s):  
T-Que Phuong Phan
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Hydrothermal Carbonization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Of Cellulose ◽  
Ft Ir ◽  
Physical And Chemical ◽  
Hydrolysis Of

In this study, a carbon–based solid acid catalyst was prepared via hydrothermal carbonization method (HTC) using glucose and pyrolysed waste tyre as carbon precursors and aqueous solution of H2SO4 as sulfonation agent. Prepared catalysts were characterized by X–ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared FT–IR and Brunauer–Emmett–Teller (BET). As the result, catalysts were manufactured with the appropriate physical and chemical characteristics and high acidity.

scholarly journals An Efficient Synthesis of Tetrahydrobenzo[b]pyran Derivatives Using Sulfonic Acid Functionalized Silica as an Efficient Catalyst

2011 ◽  
Vol 8 (1) ◽  
pp. 293-299 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Alireza Abbasi ◽  
Alireza Badiei ◽  
Zeinab Aslani
Keyword(s):  
Single Crystal ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Functionalized Silica ◽  
Efficient Synthesis ◽  
Efficient Catalyst ◽  
X Ray

Tetrahydrobenzo[b]pyran derivatives were efficiently synthesized by the reaction of appropriated aromatic aldehydes, malononitrile and dimedone in the presence of SiO2-Pr-SO3H as a nanoporous and recoverable solid acid catalyst, in good to excellent yields. Single crystal x-ray analysis conclusively confirmed the structure of the 2-amino-3-cyano-7,7-dimethyl-4-(4-methylphenyl)-5-oxo-4H-5,6,7,8-tetrahydro-benzopyran.

scholarly journals Synthesis of Polytetrahydrofuran Using Protonated Kaolin as A Solid Acid Catalyst

2019 ◽  
Vol 14 (2) ◽  
pp. 294
Author(s):  
Abdelhak Moumen ◽  
Zhour Hattab ◽  
Youghourta Belhocine ◽  
Kamel Guerfi ◽  
Nacer Rebbani
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Analytical Techniques ◽  
Acid Catalyst ◽  
Crystalline Substance ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

In this work, a non-toxic protonated kaolin clay exchanged with protons, was successfully applied as a solid acid catalyst for the polymerization of tetrahydrofuran (poly(THF)) at room temperature in the presence of acetic anhydride. Prior to using the kaolin as a catalyst, it was treated with HCl (0.1 M) and characterized using various analytical techniques. The amounts of catalyst and reaction time on the conversion of THF were investigated. Characterizations of nuclear magnetic Resonance of proton (1H-NMR), Fourier Transform Infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), Optical Microscopy (OM), and Differential Scanning Calorimetry (DSC) techniques were used to examine the resulting polymer. X-ray characterization and DSC data indicated that the obtained poly(THF) is a highly crystalline substance. The results showed that protonated kaolin (kaolin–H+) has a high catalytic activity for the polymerization of THF with a conversion rate of 50.02% after 20 hours. Copyright © 2019 BCREC Group. All rights reserved. 

Synthesis and Characterization of Heterogeneous Solid Acid Catalyst from Alstonia Scolaris Stalks for Biodiesel Production using Waste Cooking Oil

2020 ◽  
Vol 10 ◽  
Author(s):  
Charishma Venkata Sai Anne ◽  
Karthikeyan S. ◽  
Arun C.
Keyword(s):  
Reaction Time ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Wood Biomass ◽  
Waste Wood ◽  
X Ray ◽  
Cooking Oil

Background: Waste biomass derived reusable heterogeneous acid based catalysts are more suitable to overcome the problems associated with homogeneous catalysts. The use of agricultural biomass as catalyst for transesterification process is more economical and it reduces the overall production cost of biodiesel. The identification of an appropriate suitable catalyst for effective transesterification will be a landmark in biofuel sector Objective: In the present investigation, waste wood biomass was used to prepare a low cost sulfonated solid acid catalyst for the production of biodiesel using waste cooking oil. Methods: The pretreated wood biomass was first calcined then sulfonated with H2SO4. The catalyst was characterized by various analyses such as, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The central composite design (CCD) based response surface methodology (RSM) was applied to study the influence of individual process variables such as temperature, catalyst load, methanol to oil molar ration and reaction time on biodiesel yield. Results: The obtained optimized conditions are as follows: temperature (165 ˚C), catalyst loading (1.625 wt%), methanol to oil molar ratio (15:1) and reaction time (143 min) with a maximum biodiesel yield of 95 %. The Gas chromatographymass spectrometry (GC-MS) analysis of biodiesel produced from waste cooking oil was showed that it has a mixture of both monounsaturated and saturated methyl esters. Conclusion: Thus the waste wood biomass derived heterogeneous catalyst for the transesterification process of waste cooking oil can be applied for sustainable biodiesel production by adding an additional value for the waste materials and also eliminating the disposable problem of waste oils.

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

Structure Refinements of the Layered Intergrowth Phases SbIIISbV x A 1−x TiO6 (x≃0, A = Ta, Nb) Using Synchrotron X-ray Powder Diffraction Data

1997 ◽  
Vol 53 (6) ◽  
pp. 861-869 ◽  
Author(s):  
C. D. Ling ◽  
J. G. Thompson ◽  
S. Schmid ◽  
D. J. Cookson ◽  
R. L. Withers
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Homologous Series ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
The Family

The structures of the layered intergrowth phases SbIIISb^{\rm V}_xAl-xTiO6 (x \simeq 0, A = Ta, Nb) have been refined by the Rietveld method, using X-ray diffraction data obtained using a synchrotron source. The starting models for these structures were derived from those of Sb^{\rm III}_3Sb^{\rm V}_xA 3−xTiO14 (x = 1.26, A = Ta and x = 0.89, A = Nb), previously solved by single-crystal X-ray diffraction. There were no significant differences between the derived models and the final structures, validating the approach used to obtain the models and confirming that the n = 1 and n = 3 members of the family, Sb^{\rm III}_nSb^{\rm V}_xA n−xTiO4n+2 are part of a structurally homologous series.

Powder X-ray diffraction data for Ba4ZnTi11O27 and Ba2ZnTi5O13

1994 ◽  
Vol 9 (1) ◽  
pp. 56-62 ◽  
Author(s):  
C. G. Lindsay ◽  
C. J. Rawn ◽  
R. S. Roth
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Powder Samples ◽  
Unit Cell Dimensions

Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and studied using single-crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated from a least-squares refinement with a final maximum Δ2θ of 0.05°. Both phases were found to have monoclinic cells, space group C2/m. The refined lattice parameters for the Ba4ZnTi11O27 compound are a= 19.8687(8) Å, b=11.4674(5) Å, c=9.9184(4) Å, β= 109.223(4)°, and Z=4. The refined lattice parameters for the Ba2ZnTi5O13 compound are a= 15.2822(7) Å, b=3.8977(1) Å, c=9.1398(3) Å, β=98.769(4)°, and Z=2.

On racemic and L-malates: a comparison of their crystal structures

2004 ◽  
Vol 219 (2) ◽  
Author(s):  
Michel Fleck ◽  
Ekkehart Tillmanns ◽  
Ladislav Bohatý ◽  
Peter Held
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Space Group ◽  
X Ray

AbstractThe crystal structures of eight different L-malates have been determined and refined from single-crystal X-ray diffraction data. The compounds are the monoclinic (space groupIn addition, for all the compounds, powder diffraction data were collected, analysed and submitted to the powder diffraction file (PDF).

scholarly journals Gas Phase Oligomerization of Isobutene over Acid Treated Kaolinite Clay Catalyst

2017 ◽  
Vol 12 (1) ◽  
pp. 119 ◽  
Author(s):  
Dhaifallah Aldhayan ◽  
Ahmed Aouissi
Keyword(s):  
Gas Phase ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Structural Transformations ◽  
Reaction Engineering ◽  
Kaolinite Clay ◽  
X Ray ◽  
Clay Catalyst ◽  
By Products

<p>Natural Kaolin Clay was calcined and treated by sulfuric acid. The resulting solid acid catalyst was characterized by FTIR, TGA, and X-ray powder diffraction (XRD) and tested for isobutene oligomerization in a gas phase. The characterization results showed that the acid treated clay underwent chemical and structural transformations. After acid treatment, the Si/Al ratio was increased, and the crystalline raw clay became amorphous. The effects of various parameters such as reaction temperature, reaction time and contact time on isobutene oligomerization were investigated. Catalytic tests showed that isobutene oligomerization led to dimers and trimers as major products. Tetramers were obtained as by- products. At relatively high reaction temperatures and long contact times, the conversion was enhanced while the selectivity of dimers was decreased in favor of higher oligomers. Copyright © 2017 BCREC GROUP. All rights reserved</p><p><em>Received: 27<sup>th</sup> October 2016; Revised: 21<sup>st</sup> December 2016; Accepted: 22<sup>nd</sup> December 2016</em></p><p><strong>How to Cite:</strong> Aldhayan, D., Aouissi, A. (2017). Gas Phase Oligomerization of Isobutene over Acid Treated Kaolinite Clay Catalyst. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 12 (1): 119-126 (doi:10.9767/bcrec.12.1.758.119-126)</p><p><strong>Permalink/DOI</strong>: http://dx.doi.org/10.9767/bcrec.12.1.758.119-126</p><p> </p>

Sign in / Sign up

Export Citation Format

Share Document