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.

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.

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.

Selective Synthesis of Glycerol Monoester with Heteropoly Acid as a New Catalyst

2012 ◽  
Vol 545 ◽  
pp. 373-378 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Manal Ismail ◽  
Norasikin Mohd Nordin ◽  
Nadia Farhana Adnan ◽  
Jamaliah Mohd Jahim ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Heteropoly Acid ◽  
Solid Acid ◽  
Ph Value ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Esterification Reaction ◽  
Homogeneous Catalyst ◽  
Selective Synthesis

In this work, we were study the selective synthesis of GME from oleic acid and glycerol using two types of solid heteropoly acid catalysts, namely silicotungstic acid bulk (STAB) and STA-silica sol gel (STA-SG). The performance and selectivity of STAB and STA-SG in the esterification reaction have been investigated and compared to the sulphuric acid (H2SO4) as conventional homogeneous catalyst. The catalysts were then characterized their physical and chemical properties using BET, XRD, TEM and XPS. XPS analyses were shown 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 in terms of the relatively lower pH value (pH 3.7) than the STAB (pH 2.8). 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 %, 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.

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by Perchlorated Zirconia (HClO4/ZrO2) nanoparticles as a novel solid acid catalyst

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Seyed Yousef Mosavian
Keyword(s):  
Solid Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Zro2 Nanoparticles ◽  
Calcination Temperatures ◽  
Aldehydes And Ketones

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.

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

scholarly journals Preparation of the WOX/MCM-41 Solid Acid Catalyst and the Catalytic Performance for Solketal Synthesis

ACS Omega ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 3875-3883
Author(s):  
Yixuan Huang ◽  
Guangcai Zhang ◽  
Qinhui Zhang
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Mcm 41

scholarly journals Titanate nanotubes-bonded organosulfonic acid as solid acid catalyst for synthesis of butyl levulinate

RSC Advances ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 3657-3662 ◽  
Author(s):  
Shuolin Zhou ◽  
Dabo Jiang ◽  
Xianxiang Liu ◽  
Yiping Chen ◽  
Dulin Yin
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Titanate Nanotubes ◽  
Esterification Reaction ◽  
Hybrid Catalyst

TiO2 nanotubes-bonded organosulfonic acid as a hybrid catalyst exhibited better activity and good reusability for esterification reaction.

scholarly journals Optimization of Biodiesel Production from Waste Cooking Oil Using S–TiO2/SBA-15 Heterogeneous Acid Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 67 ◽  
Author(s):  
Muhammad Hossain ◽  
Md Siddik Bhuyan ◽  
Abul Md Ashraful Alam ◽  
Yong Seo
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Catalyst Loading ◽  
Esterification Reaction ◽  
Impregnation Method ◽  
Cooking Oil ◽  
Heterogeneous Acid Catalyst

The aim of this research was to synthesize, characterize, and apply a heterogeneous acid catalyst to optimum biodiesel production from hydrolyzed waste cooking oil via an esterification reaction, to meet society’s future demands. The solid acid catalyst S–TiO2/SBA-15 was synthesized by a direct wet impregnation method. The prepared catalyst was evaluated using analytical techniques, X-ray diffraction (XRD), Scanning electron microscopy (SEM) and the Brunauer–Emmett–Teller (BET) method. The statistical analysis of variance (ANOVA) was studied to validate the experimental results. The catalytic effect on biodiesel production was examined by varying the parameters as follows: temperatures of 160 to 220 °C, 20–35 min reaction time, methanol-to-oil mole ratio between 5:1 and 20:1, and catalyst loading of 0.5%–1.25%. The maximum biodiesel yield was 94.96 ± 0.12% obtained under the optimum reaction conditions of 200 °C, 30 min, and 1:15 oil to methanol molar ratio with 1.0% catalyst loading. The catalyst was reused successfully three times with 90% efficiency without regeneration. The fuel properties of the produced biodiesel were found to be within the limits set by the specifications of the biodiesel standard. This solid acid catalytic method can replace the conventional homogeneous catalyzed transesterification of waste cooking oil for biodiesel production.

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