Synthesis of Acetals and Ketals Catalyzed by H4SiW6Mo6O40/SiO2

2012 ◽  
Vol 430-432 ◽  
pp. 289-292
Author(s):  
Shui Jin Yang ◽  
Li Yu ◽  
Yong Kui Huang ◽  
Guo Bin Duan
Keyword(s):  
High Activity ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Reusable Catalyst ◽  
Reaction Parameters ◽  
Catalytic Application ◽  
Heterogeneous Acid Catalyst ◽  
Gel Technique ◽  
Optimized Conditions

Heterogeneous acid catalyst, H4SiW6Mo6O40/SiO2 was synthesized by a sol-gel technique. Catalytic application of the catalyst for synthesis of acetals and ketals were tested. The variation of different reaction parameters on the yield of acetals and ketals were also studied. The yields of acetals and ketals can reach 80.0%~96.9% at the optimized conditions. The high activity and stability of the catalyst is well retained after 4 runs. The results reveal that the H4SiW6Mo6O40/SiO2 catalysis is a novel, effective and reusable catalyst for synthesizing actetals and ketals.

Catalytic Application of H4SiW12O40/SiO2 in Synthesis of Acetals and Ketals

2011 ◽  
Vol 284-286 ◽  
pp. 2374-2379 ◽  
Author(s):  
Shui Jin Yang ◽  
Yong Kui Huang ◽  
Li Yu
Keyword(s):  
Reaction Time ◽  
High Activity ◽  
Sol Gel ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
Catalytic Application ◽  
Ft Ir ◽  
Gel Technique ◽  
Catalyst Dosage ◽  
Novel Catalyst

A novel catalyst, H4SiW12O40/SiO2was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of H4SiW12O40/SiO2for synthesis of acetals and ketals were tested. The variation of different reaction parameters, such as mole ratio of aldehyde/ketone to alcohols, catalyst dosage and reaction time on the yield of acetals and ketals were also studied. The results reveal that the H4SiW12O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions and the high activity and stability of the catalyst is well retained on recycling.

Catalytic Synthesis of N-Butyl Methacrylate with H4SiW6Mo6O40/SiO2

2013 ◽  
Vol 631-632 ◽  
pp. 135-139 ◽  
Author(s):  
Li Yu ◽  
Yong Kui Huang ◽  
Guo Bin Duan ◽  
Shui Jin Yang
Keyword(s):  
Orthogonal Design ◽  
Sol Gel ◽  
Catalytic Synthesis ◽  
Butyl Methacrylate ◽  
Molar Ratio ◽  
Reaction Parameters ◽  
Catalytic Application ◽  
Ft Ir ◽  
Gel Technique ◽  
Optimized Conditions

A novel environmental friendly catalyst, H4SiW6Mo6O40/SiO2was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of the catalyst for synthesis of n-butyl methacrylate was investigated. The variation of different reaction parameters were studied by orthogonal design. Under optimized conditions, that is, molar ratio of methacrylic acid to n-butanol is 1:1.7, catalyst dosage is 0.75 %, volume of cyclohexane is 12 mL and the reaction time is 2.5 h, the yield of n-butyl methacrylate reaches 85.3%. The results reveal that the H4SiW6Mo6O40/SiO2O2 catalysis is an execellent catalyst for synthesis of n-butyl methacrylate. Introduction

Tungstophosphoric Acid Entrapped on Mesoporous Silica via Sol Gel Technique

2006 ◽  
Vol 11-12 ◽  
pp. 69-72
Author(s):  
Joon Ching Juan ◽  
Yarmo Mohd Ambar ◽  
Jing Chang Zhang
Keyword(s):  
Mesoporous Silica ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Chemical Properties ◽  
Acid Catalyst ◽  
Tungstophosphoric Acid ◽  
Esterification Reaction ◽  
Heterogeneous Acid Catalyst ◽  
Gel Technique

The heterogeneous 12-tungstophosphoric acid (HPW) catalyst is becoming important in industrial processes for example in esterification reaction. A novel solid acid catalyst of HPW entrapped on mesoporous silica was synthesized by sol gel technique. Neutral template dodecylamine was introduced to obtain mesopores structure catalyst. The physical and chemical properties of the catalyst were characterized by XRD, nitrogen sorption and FTIR. In conclusion, this new type of mesoporous solid acid catalyst is a very promising heterogeneous acid catalyst for esterification reaction involving bulky molecules such as fatty acid.

scholarly journals Volcanic ash as reusable catalyst in the green synthesis of 3H-1,5-benzodiazepines

2019 ◽  
Vol 8 (1) ◽  
pp. 600-610 ◽  
Author(s):  
Mercedes Muñoz ◽  
Gustavo Pasquale ◽  
Angel Gabriel Sathicq ◽  
Gustavo Pablo Romanelli ◽  
Carmen Inés Cabello ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Textural Properties ◽  
Acid Catalyst ◽  
Reusable Catalyst ◽  
Volcanic Complex ◽  
Mountain Range ◽  
Catalytic Materials ◽  
The Andes ◽  
Solvent Free Conditions ◽  
Heterogeneous Acid Catalyst

Abstract The volcanic ash from the Andes mountain range (Puyehue-Cordon Caulle volcanic complex situated in western South America on the Argentinean-Chilean border) was used as heterogeneous acid catalyst in the suitable synthesis of 3H-1,5-benzodiazepines. The natural ashes were classified according to their particle size to generate the different catalytic materials. The catalysts were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), vibrational spectroscopies (FT-IR and Raman), and textural properties were determined by N2 adsorption (SBET). Potentiometric titration with n-butylamine was used to determine the acidic properties of the catalytic materials. Several 3H-1,5-benzodiazepines were obtained by reaction of o-phenylenediamine and substituted 1,3-diphenyl-1,3-propanedione in solvent-free conditions, giving good to excellent yields of a variety benzodiazepines. The method was carried out in environmentally friendly conditions and it was operationally simple. The volcanic ash resulted in a safe and recyclable catalyst.

scholarly journals Synthesis, Characterization and Catalytic Performance ofH3SiW12O40/SiO2Prepared by Sol-Gel Technique

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
W. N. R. W. Isahak ◽  
M. Ismail ◽  
N. M. Nordin ◽  
J. M. Jahim ◽  
M. A. Yarmo
Keyword(s):  
Heteropoly Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Environmentally Benign ◽  
Esterification Reaction ◽  
Silicotungstic Acid ◽  
Gel Technique

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.

Niobium phytate prepared from phytic acid and NbCl5: a highly efficient and heterogeneous acid catalyst

2016 ◽  
Vol 6 (4) ◽  
pp. 1070-1076 ◽  
Author(s):  
Zhimin Xue ◽  
Yuwei Zhang ◽  
Guofeng Li ◽  
Jinfang Wang ◽  
Wancheng Zhao ◽  
...  
Keyword(s):  
High Activity ◽  
Phytic Acid ◽  
Carbonyl Compounds ◽  
Acid Catalyst ◽  
Highly Efficient ◽  
Heterogeneous Acid Catalyst

Niobium phytate, designed from phytic acid and NbCl5, showed high activity for cyanosilylation of carbonyl compounds and dehydration of carbohydrates.

scholarly journals Chromium oxide zirconia solid acid catalyst for n-pentane isomerization

2014 ◽  
Vol 10 (4) ◽  
Author(s):  
Nur Hazirah Rozali Annuar ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono
Keyword(s):  
Physical Properties ◽  
Surface Area ◽  
Chromium Oxide ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Bet Surface Area ◽  
Gel Technique

New catalyst based on zirconia (ZrO2) supported by chromium oxide (CrO3) for isomerization of n-pentane was studied. CrO3-ZrO2 was prepared with chromium nitrate by the titration and sol-gel technique. The physical properties of the catalysts were characterized by XRD, BET surface area analyzer, and TEM. The acidity and structure of catalysts were determined by pyridine and lutidine preadsorbed FTIR spectroscopy.  The isomerization of n-pentane was carried out at 523 K under hydrogen stream. CrO3-ZrO2 shows the differences in terms of physical properties where the introduction CrO3 partially eliminated the monoclinic phase of ZrO2 and developed new peaks assigned to tetragonal phase of ZrO2. CrO3-ZrO2 also shows a higher specific surface area where it increases in the pore volume of the catalyst compare to its parent zirconia.  The IR results indicated that CrO3-ZrO2 catalyst have strong Lewis and weak Brønsted acid sites. The conversion of n-pentane for CrO3-ZrO2 was 32% respectively, while the selectivity to iso-pentane was 100%. ________________________________________GRAPHICAL ABSTRACT

Synthesis and Characterization of Silicotungstic Acid Nanoparticles via Sol Gel Technique as a Catalyst in Esterification Reaction

2011 ◽  
Vol 364 ◽  
pp. 266-271 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Ismail Manal ◽  
Norasikin Mohd Nordin ◽  
Noraini Hamzah ◽  
Khadijeh Beigom Ghoreishi ◽  
...  
Keyword(s):  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Esterification Reaction ◽  
Homogeneous Catalyst ◽  
Silicotungstic Acid ◽  
Gel Technique ◽  
Glycerol Monooleate

Glycerol monooleate (GMO) as an esterification product of oleic acid and glycerol is highly potential as an anti-friction substance in the engine lubricant. The purpose of this work is to study the synthesis, characterization and catalytic performance of solid heteropoly acid catalysts, namely silicotungstic acid bulk (STAB) and STA-silica sol gel (STA-SG). The activity and selectivity of STAB and STA-SG in the esterification reaction have been investigated and compared to the homogeneous catalyst i.e. sulphuric acid (H2SO4). The synthesized catalysts were characterized by BET, XRD, TEM, XPS and TPD-NH3. BET analyses shown that the STA-SG catalyst is very high in surface area compared to STAB of 460.11 m2/g and 0.98 m2/g, respectively. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W and Si-O-Si bonding in STA-SG compared to that in STAB. The main species of O1s (90.74 %, 531.5 eV) followed by other O1s peak (9.26 %, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98%, while lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94%, while significantly higher GME selectivity of 95% rendering it the more efficient solid acid catalyst.

Catalytic Application of H3PW6Mo6O40/SiO2 in Synthesis of Acetals and Ketals

2012 ◽  
Vol 531 ◽  
pp. 304-307
Author(s):  
Yong Kui Huang ◽  
Li Yu ◽  
Guo Bin Duan ◽  
Yun Zhi Wang ◽  
Ming Bo Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sol Gel ◽  
Orthogonal Experimental Design ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Preparation Conditions ◽  
Catalytic Application ◽  
Gel Technique ◽  
Novel Catalyst

A novel catalyst, H3PW6Mo6O40/SiO2was prepared by a sol-gel technique and its catalytic application in synthesis of acetals and ketals were tested. The preparation conditions of catalyst were optimised by using the orthogonal experimental design. The optimum conditions are: the mass ratio of H3PW6Mo6O40 to SiO2is 0.4, calcination temperature is 150 °C and calcination time is 3 h. The steric properties of the reactants play an important role in the acetalization. The catalytic activity of the catalyst decreases when the size of the reactant increased. Although a decrease in catalytic activity was observed with its subsequent reuse, the catalyst could be reused at least four times without any other treatments. The results reveal that the H3PW6Mo6O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions.

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