Comparative Synthesis and Characterization of Nanostructured SAPO-34 Using TEA and Morpholine: Effect of Mono vs. Dual Template on Catalytic Properties and Performance toward Methanol to Light Olefins

2020 ◽  
Vol 23 ◽  
Author(s):  
Sogand Aghamohammadi ◽  
Mohammad Haghighi ◽  
Parisa Sadeghpour ◽  
Tayebeh Souri
Keyword(s):  
Molecular Sieves ◽  
Synthesis Method ◽  
Life Time ◽  
Light Olefins ◽  
Molar Ratio ◽  
And Performance ◽  
Light Olefins Selectivity ◽  
Mixed Template ◽  
Mto Process

Aim and Objective: Production of light olefins from methanol was studied over SAPO-34 molecular sieves exploring the effect of mono and dual templates. Herein, the single templates of TEA, morpholine and mixed template of TEA/morpholine (equal molar ratio of TEA and morpholine) were used to synthesize SAPO-34 catalysts. Materials and Methods: The prepared samples were prepared via hydrothermal synthesis method and characterized with XRD, FESEM, PSD, EDX, BET and FTIR techniques. Results: It was found that the crystallinity decreased upon applying TEA as template and also it can be noted that the intensity of the SAPO-34 phase peaks increased by increasing the morpholine in template mixture. Production of much smoother particles for the catalyst synthesized with binary template mixture of TEA/morpholine can be depended on the crystallinity increase. Si incorporation value was decreased for the catalyst with a major phase of SAPO-5 (topological structure of AFI). It is indicative that the TEA application would facilitate the formation of AFI structure which is incapable of the incorporating higher amounts of Si in to the crystallite framework. Conclusion: The nature of the template determines the morphology of final product due to different rate of crystal growth obtained in accordance with XRD and FESEM results. Therefore, the catalyst synthesized with TEA/morpholine mixture shows the best performance among synthesized samples in terms of life time in the MTO process sustaining light olefins selectivity at higher values (about 90% after 630 min TOS).

scholarly journals Low Temperature NH3-SCR over Mn-Ce Oxides Supported on MCM-41 from Diatomite

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3654 ◽  
Author(s):  
Mingxuan Ma ◽  
Xiaoyu Ma ◽  
Suping Cui ◽  
Tingting Liu ◽  
Yingliang Tian ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Synthesis Method ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Catalyst Carrier ◽  
Nh3 Scr ◽  
Catalytic Material ◽  
Lewis Acidic Sites ◽  
Acidic Sites ◽  
Mcm 41

A series of MCM-41 molecular sieves with different molar ratio of template to silicon were synthesized through hydrothermal synthesis method by using cetyltrimethylammonium bromide (CTAB) as the template, diatomite as the silicon source. By using impregnation method, the Mn-Ce/MCM-41 SCR molecular sieve-based catalysts were prepared. The results observed that when the molar ratio of template to silicon was 0.2:1, the MCM-41 as catalyst carrier has the highest surface area and largest pore volume, it also presented typically ordered hexagonal arrays of uniform channels. The denitration catalytic material based on this carrier has a high number of Lewis acidic sites, and the denitration efficiency can reach more than 93%.

Synthesis, Characterization of Phenethyltrimethoxysilane (PE) Modified Organic-Inorganic Hybrid Silicalite-1 Molecular Sieves and its Transformation into Solid Acid Materials

2008 ◽  
Vol 47-50 ◽  
pp. 238-241
Author(s):  
Y.F. Yeong ◽  
A.Z. Abdullah ◽  
A.L. Ahmad ◽  
S. Bhatia
Keyword(s):  
Molecular Sieves ◽  
Solid Acid ◽  
Nanoporous Materials ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
Silica Source ◽  
One Step ◽  
Titration Technique

Organic-inorganic hybrid nanoporous materials with silicalite-1 structure were synthesized in one step co-condensation technique and subsequent transformed into solid acid materials. The tetraethoxysilane (TEOS) was used as the primary inorganic silica source with the phenethyltrimethoxysilane (PE) as an organic modifier. The effect of the PE presence in the initial synthesis mixture was studied by varying the molar ratio of PE to TEOS in the range of 0.05 to 0.20. The resulting organic-inorganic hybrid materials were characterized for its crystallinity (X-ray diffraction, XRD), surface morphology (scanning electron microscopy, SEM) and elemental composition (elemental analysis). The degree of chemical interactions between the organic and inorganic phases was determined by Fourier transform infrared spectroscopy (FTIR). The acid strength of the organic-inorganic hybrid solid acid materials was also obtained by titration technique.

Synthesis and Characterization of Manganese Phosphate Aluminosilicate Molecular Sieve

2014 ◽  
Vol 665 ◽  
pp. 264-266
Author(s):  
Wu Kui Luo ◽  
Shao Ming Ying ◽  
Mei Zhen Zhou
Keyword(s):  
Molecular Sieve ◽  
Synthesis Method ◽  
Raw Material ◽  
Molar Ratio ◽  
Manganese Acetate ◽  
Crystallization Time ◽  
Good Thermal Stability ◽  
Manganese Phosphate ◽  
Crystallization Conditions

Using conventional hydrothermal synthesis method, n-butylamine as an organic templating agent (C4H11N), phosphoric acid, tetraethyl orthosilicate, aluminum hydroxide, and manganese acetate as starting material, by adjusting the amount of the crystallization conditions and reactants pH, phosphate synthesized manganese-containing aluminosilicate zeolite. The molar ratio between the raw material is n (P): n (Si): n (Al): n (Mn): n (H2O): n (C4H11N) = (1.8 ~ 2.2): (0.15 ~ 0.2): (0.8 ~ 0.9): (0.6 ~ 0.8): (2.4 ~ 4.5): (1.1 ~ 1.4), pH in the range of 5.30 ~ 5.50, the crystallization temperature was 150 °C ~ 170 °C, the crystallization time is 24 ~ 30 h, the curve indicated by DSC-TG, synthesized molecular sieve obtained with a more good thermal stability.

scholarly journals Characterization of Butanediol-Alginate Ester as Candidate of Hemodialysis Membrane

2015 ◽  
Vol 15 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Choirul Amri ◽  
Mudasir Mudasir ◽  
Dwi Siswanta ◽  
Roto Roto
Keyword(s):  
Mechanical Properties ◽  
Protein Adsorption ◽  
Platelet Adhesion ◽  
Membrane Surface ◽  
Molar Ratio ◽  
And Performance ◽  
Hemodialysis Membrane ◽  
Better Than ◽  
Membrane Mechanical Properties

An ester of butanediol-alginate has been studied as a possible hemodialysis membrane. With 1,4-butanediol molar ratio of 0.1, 0.5, and 1.0, it showed that the membrane mechanical properties, stability, protein adsorption, platelet adhesion and performance for urea and creatinine clearance are better than that of unmodified alginate. The increase in 1,4-butanediol molar ratio causes hemodialysis ratio to improve, and causes protein adsorption and platelet adhesion at the membrane surface to decrease. In the case of protein adsorption and platelet adhesion, the membrane with the molar ratio of 1.0 has better hemocompatibility properties. In the hemodialysis test for 4 h, using 2.742 mg cm-2 h-1 of urea and 0.058 mg cm-2 h-1 of creatinine flux, this membrane showed that 48.5% of urea and 44.2% of creatinine were cleaned.

scholarly journals Characterization of the structure and performance of Ce3+ exchanged lix molecular sieves

2018 ◽  
Vol 52 (4) ◽  
pp. 423-428
Author(s):  
M. Jiang ◽  
M. Zhu ◽  
C. Deng ◽  
J. Ma ◽  
Q. Duan ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
And Performance

scholarly journals Enhancement of Light Olefins Selectivity Over N-Doped Fischer-Tropsch Synthesis Catalyst Supported on Activated Carbon Pretreated with KMnO4

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 505
Author(s):  
Zhipeng Tian ◽  
Chenguang Wang ◽  
Zhan Si ◽  
Chengyan Wen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Carbon Support ◽  
Tropsch Synthesis ◽  
Light Olefins ◽  
Molar Ratio ◽  
Iron Nitride ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Suppression Effect ◽  
Light Olefins Selectivity

Ammonium iron citrate was used as an iron precursor in order to prepare N-doped catalysts supported on KMnO4 pretreated activated carbon (10MnK-AC). Iron nitride was synthesized in company with the formation of α-Fe2O3 on 10MnK-AC. The characterizations of the catalysts show that nitrogen atoms were doped into iron lattice rather than the networks of the carbon support. The performance of Fischer-Tropsch synthesis to light olefins (FTO) suggest an improvement in O/P ratio (olefins to paraffins molar ratio of C2–C4) over the iron catalysts supported on 10MnK-AC. The further promotion of light olefins selectivity (up to 44.7%) was obtained over FeN-10MnK-AC catalyst owing to the collaborative contribution of the electron donor effect of nitrogen and the suppression effect on the second hydrogenation over 10MnK-AC support.

Catalytic Synthesis of n-Butyl Oleate by Cerium Complex Doped Y/SBA-15 Composite Molecular Sieve

2018 ◽  
Vol 37 (2) ◽  
pp. 107-111 ◽  
Author(s):  
Chunwei Shi ◽  
Xue Bian ◽  
Yongfu Wu ◽  
Yufeng Cong ◽  
Mingyuan Pei
Keyword(s):  
Oleic Acid ◽  
Composite Materials ◽  
Reaction Time ◽  
Molecular Sieves ◽  
Thermo Gravimetric Analysis ◽  
Synthesis Method ◽  
Hexagonal Structure ◽  
Mesoporous Molecular Sieves ◽  
Molar Ratio ◽  
Gravimetric Analysis

AbstractCerium ion was successfully incorporated into Y/SBA-15 micro-mesoporous molecular sieves via the hydrothermal synthesis method to give a series of composite materials. The prepared materials were thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and differential thermo gravimetric analysis (TG-DTG). The results showed that the prepared composite materials retained the highly ordered mesoporous two-dimensional hexagonal structure of SBA-15 and the octagonal structure of Y. The catalyst Ce-Y/SBA-15 was prepared and characterized, then the esterification of n-butanol and oleic acid was studied with bismuth phosphotungstate as a catalyst. Using this model reaction, the effects of Ce-HY/SBA-15, molar ratio of alcohol to oleic acid, amount of catalysts, reaction time and reaction temperature were investigated. The experimental results show that the optimal reaction conditions were: 1.8:1 molar ratio of alcohol to acid, 5 % catalyst amount (based on weight of oleic acid), 4 h reaction time and reflux conditions. Under these conditions, the yield of esterification was 90.6 %. The results suggest that the addition of Ce can effectively improve the catalytic properties of composite molecular sieves.

Synthesis and Characterization of a Nanostructured Matrix of Hydrated Calcium Phosphate

2016 ◽  
Vol 881 ◽  
pp. 159-164
Author(s):  
Maicon Douglas Possamai ◽  
Nelson Heriberto Almeida Camargo ◽  
Daiara Floriano-Silva ◽  
Marli Baltazar Roesler Eckstein ◽  
Priscila Ferraz Franczak
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Rays ◽  
Crystallographic Characteristics ◽  
Characterization Studies ◽  
Wet Synthesis ◽  
Hydrated Calcium

Bone reconstruction biomaterials are topics of interest in dentistry, orthopedics, scientific, commercial. The most popular bone repairing and reconstruction biomaterials are calcium phosphates. The demand for biomaterials is associated with the chemical and crystallographic characteristics of the human bone apatite. The wet synthesis method is common in the production of nanostructured powders of hydrated calcium phosphates, providing nanoparticles with sizes less than 50nm. This study aimed to synthesize and characterize hydrated calcium phosphate powders in the molar ratio of Ca/P = 1.67. After calcination at temperature 900°C/2h, these powders provide nanostructured hydroxyapatite matrix. The characterization studies were performed with Scanning Electron Microscopy, X-rays diffraction and Infrared Spectroscopy by Fourier Transform. The results show that the synthesis method provides hydrated calcium phosphate powders formed by aggregated and agglomerated nanoparticles. The thermal treatment of hydrated calcium phosphate powder led to formation of hydroxyapatite matrix.

Investigating the mixing sequence and the Si content in SAPO-34 synthesis for selective conversion of methanol to light olefins using morpholine &/ TEAOH templates

RSC Advances ◽  
2016 ◽  
Vol 6 (21) ◽  
pp. 17583-17594 ◽  
Author(s):  
Mohammad Ghavipour ◽  
Amin Soleimani Mehr ◽  
Yao Wang ◽  
Reza Mosayebi Behbahani ◽  
Saeed Hajimirzaee ◽  
...  
Keyword(s):  
Light Olefins ◽  
Selective Conversion ◽  
Methanol To Olefin ◽  
Gel Preparation ◽  
Si Content ◽  
Mixed Template ◽  
Mixing Sequence ◽  
Template Methods ◽  
Mto Process

SAPO-34 as the commercialized catalyst of methanol to olefin (MTO) process was synthesized by single and mixed-template methods using TEAOH and morpholine. The mixing sequence in gel preparation and the optimum Si content were investigated.

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