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 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.

New Silica Supported HClO4 as Efficient Catalysts for Estolide Synthesis from Oleic Acid

2010 ◽  
Vol 173 ◽  
pp. 140-145 ◽  
Author(s):  
Nor Asikin Mohamad Nordin ◽  
Nadia Farhana Adnan ◽  
Aznira Alias ◽  
Wan Nor Roslam Wan Isahak ◽  
Jumat Salimon ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Perchloric Acid ◽  
Solid Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Experimental Findings

The syntheses of estolides via condensation reaction of oleic acid were investigated using heterogenous catalysts. In this study HClO4 is supported onto suitable support to make it environmentally friendly. A series of solid acid catalyst containing 5-45 % of perchloric acid supported onto silica was synthesized and characterized using XRD, BET surface area measurement, TEM and XPS surface analysis. Silica modified with perchloric acid was found to be efficient and environmentally benign solid acid catalyst for estolide synthesis. The reaction was performed at 70 oC for 10 hours to give oleic-oleic monoestolide acid (m/z 563.51 as M-H)-. Based on the experimental findings above, optimum catalytic performance was with 15 % HClO4 loading onto SiO2 to give 98.98 % conversion of the oleic acid with 63.98 % oleic-oleic monoestolide acid selectivity.

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

Nanosized sulfated zirconia as solid acid catalyst for the synthesis of 2-substituted benzimidazoles

2013 ◽  
Vol 67 (5) ◽  
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Mohammad Hajihakimi
Keyword(s):  
Sulfated Zirconia ◽  
Tetragonal Phase ◽  
Solid Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Ft Ir

AbstractThe condensation reaction of o-phenylenediamine and arylaldehydes was investigated in the presence of nanosized sulfated zirconia (SO42−-ZrO2) as the solid acid catalyst. Nanosized SO42−-ZrO2 was prepared and characterized by the XRD, FT-IR, and SEM techniques. The results confirm good stabilization of the tetragonal phase of zirconia in the presence of sulfate. Reusability experiments showed partial deactivation of the catalyst after each run; good reusability can be achieved after calcinations of the recovered catalyst before its reuse.

scholarly journals Preparation of a novel solid acid catalyst with Lewis and Br{\o}nsted acid sites and its application in acetalization

2014 ◽  
Vol 38 ◽  
pp. 157-163 ◽  
Author(s):  
Yijun DU ◽  
Linjun SHAO ◽  
Lingyan LUO ◽  
Si SHI ◽  
Chenze QI
Keyword(s):  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Acid Sites

scholarly journals Acid Properties of GO and Reduced GO as Determined by Microcalorimetry, FTIR, and Kinetics of Cellulose Hydrolysis-Hydrogenolysis

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1393
Author(s):  
Van Chuc Nguyen ◽  
Sarah Kheireddine ◽  
Amar Dandach ◽  
Marion Eternot ◽  
Thi Thu Ha Vu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
High Mobility ◽  
Acid Catalyst ◽  
Strong Acid ◽  
Cellulose Hydrolysis ◽  
Acid Sites ◽  
Pyridine Adsorption ◽  
Nh3 Adsorption

Graphene oxide addresses increasing interests as a solid acid catalyst working in water for carbohydrate conversion. If there is a general agreement to correlate its unique catalytic performances to its ability to adsorb sugars, the origin of its acidity remains controversial. In this article, we study the acid strength of graphene oxide (GO) prepared by modified Hummers method and that of reduced GO by calorimetry of NH3 adsorption and by FTIR of pyridine adsorption. Very strong acid sites are detected on GO by calorimetry, while reduced graphene oxide (reGO) is not very acidic. The FTIR of pyridine adsorption shows the prevailing presence of Br∅nsted acid sites and a unique feature, the presence of pyridine coordinated by hydrogen bonds. This exceptionally strong Br∅nsted acidity is tentatively explained by the presence of graphene domains decorated by hydroxyl, carboxylic, or sulfonated groups within the GO sheet, resulting in a high mobility of the negative charges which makes the proton free and explains its strong acidity. Accordingly, only GO is active and selective for native cellulose hydrolysis, leading to 27% yield in glucose. Finally, we show that sugar alcohols cannot be formed directly from cellulose using GO combined with Pt/re-GO under hydrogen, explained by the reduction of oxygenated functions of GO. The instability of the functional groups of GO in a reducing atmosphere is the weak point of this peculiar solid acid.

scholarly journals Synthesis of Sulfonic Acid-Functionalized Zirconium Poly(Styrene-Phenylvinyl-Phosphonate)-Phosphate for Heterogeneous Epoxidation of Soybean Oil

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 710 ◽  
Author(s):  
Xiaochuan Zou ◽  
Xuyuan Nie ◽  
Zhiwen Tan ◽  
Kaiyun Shi ◽  
Cun Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Soybean Oil ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Thiol Group ◽  
Catalytic Performance ◽  
X Ray ◽  
Sulfonic Acid Groups

In this paper, a solid acid catalyst (ZPS–PVPA–SO3H) was prepared by anchoring thiol group on zirconium poly(styrene-phenylvinyl-phosphonate)-phosphate (ZPS–PVPA), followed by oxidation of thiol groups to obtain sulfonic acid groups. The solid acid catalyst was characterized by XPS, X-ray, EDS, SEM, and TG-DSC. The successful preparation of sulfonic acid-functionalized ZPS–PVPA was confirmed. Subsequently, the catalytic performance of ZPS–PVPA–SO3H was investigated in the epoxidation of soybean oil. The results demonstrated that ZPS–PVPA–SO3H can effectively catalyze epoxidation of soybean oil with TBHP as an oxidant. Moreover, there was no significant decrease in catalytic activity after 5 repeated uses of the ZPS–PVPA–SO3H. Interestingly, the ZPS–PVPA–SO3H was kept in 2 mol/L of HCl overnight after the end of the seventh reaction, and the catalytic activity was gradually restored during the eighth to tenth cycles.

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