Improved Catalytic Activity and Stability Using Mixed Sulfonic Acid- and Hydroxy-Bearing Polymer Brushes in Microreactors

2014 ◽  
Vol 6 (12) ◽  
pp. 9386-9392 ◽  
Author(s):  
Roberto Ricciardi ◽  
Rajesh Munirathinam ◽  
Jurriaan Huskens ◽  
Willem Verboom
2020 ◽  
Vol 44 (39) ◽  
pp. 16810-16820
Author(s):  
Rosanna Viscardi ◽  
Vincenzo Barbarossa ◽  
Daniele Mirabile Gattia ◽  
Raimondo Maggi ◽  
Giovanni Maestri ◽  
...  

Superiorty of the supported sulfonic acid catalyst in terms of the water resistance and efficiency of the acid sites compared to the commercial reference.


2011 ◽  
Vol 314-316 ◽  
pp. 1459-1462 ◽  
Author(s):  
Jian Hui Zhou ◽  
Yu Jing Lu ◽  
Bao Hua Huang ◽  
Yan Ping Huo ◽  
Kun Zhang

Preparation of biodiesel from tung oil catalyzed by five Brǒnsted acidic ionic liquids (ILs) with propyl sulfonic acid group was investigated. These ILs show good catalytic activity for the transeserification of tung oil. Among these ILs, [C3SO3Hmim]HSO4 showed a highest catalytic activity. In addition, these ionic liquids had a good reusability and could be easily separated from the biodiesel.


Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 710 ◽  
Author(s):  
Xiaochuan Zou ◽  
Xuyuan Nie ◽  
Zhiwen Tan ◽  
Kaiyun Shi ◽  
Cun Wang ◽  
...  

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.


2021 ◽  
Vol 18 ◽  
Author(s):  
Princy Gupta ◽  
Nayan Prakash ◽  
Yogeshwar Ramawat ◽  
Palvi Rajput ◽  
Amir Fayaz ◽  
...  

: Naturally occurring clay halloysite is used to synthesize novel halloysite functionalized sulfonic acid in two steps; functionalization followed by oxidation and its catalytic activity is estimated for one-pot synthesis of Hantzsch 1,4-dihydropyridines under green solvent-free conditions. Spectroscopic studies such as FTIR, TGA, elemental analysis and first-principles based quantum chemical studies are used to characterize the catalyst. Recyclability without significant loss of catalytic activity is observed for several runs.


2021 ◽  
Vol 18 ◽  
Author(s):  
Shefa Mirani Nezhad ◽  
Seied Ali Pourmousavi ◽  
Ehsan Nazarzadeh Zare

: A highly efficient heterogeneous nanocatalyst based on modified poly (styrene-alt-maleic anhydride) (MPSAMA) in three steps was fabricated. Then, the MPSAMA surface was modified using chlorosulfonic acid (CAS) to achieve a sulfonated MPSAMA (SMPSAMA) with high acidity and efficiency. FT-IR spectroscopy, CHNS analysis, FESEM, and TGA were employed to characterize the prepared nanocatalyst. The catalytic activity of the SMPSAMA was examined for the formation of the polyhydroquinoline derivatives through Hantzsch condensation and the synthesis of 2-amino-4H-chromene derivatives. This new heterogeneous nanocatalyst has been efficiently used for the synthesis of bifunctional bis polyhydroquinoline, and new alkylene bridging bis 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran derivatives.


1972 ◽  
Vol 50 (4) ◽  
pp. 352-362 ◽  
Author(s):  
V. S. Gupta ◽  
J. B. Meldrum

Thymidylate synthetase of pig thymus has been separated into two principal forms (designated I and II, based on their order of elution) by chromatography on CM-Sephadex. By the use of (NH4)2SO4 the synthetase activity was separated into two fractions, and these were further purified by gel filtration using Sephadex G-100 and chromatography on CM-Sephadex. The highest specific activity obtained for I and II was 10.4 and 16.3 μmol of thymidine-5′-phosphate per hour per milligram of protein at 25° and pH 7.3 which represents a purification of 1680- and 2630-fold, respectively. Electrophoretically, I and II appear to be 70–80% pure. The Michaelis constants of 7.4 × 10−6 M, 1.7 × 10−5 M, and 1.8 × 10−4 M for II with respect to deoxyuridine-5′-phosphate, 5,10-methlenetetrahydrofolate, and uridine-5′-phosphate, respectively, have been determined. A double pH optima in the range of 6.6–6.8 and 7.2–7.4 in 2-N-morpholinoethane sulfonic acid buffer was exhibited by both forms. Forms I and II showed maximal catalytic activity only in the presence of sulfhydryl compounds (60 mM) and also had the ability to methylate uridine-5′-phosphate, although at a slower rate (ca. 28% and 13%, respectively) compared with the rate of methylation of deoxyuridine-5′-phosphate. Both deoxyuridine-5′-phosphate and tetrahydrofolate (to a lesser extent) afforded protection to II against heat inactivation.


Sign in / Sign up

Export Citation Format

Share Document