scholarly journals Chemical grafting of sulfo groups onto carbon fibers

2019 ◽  
Vol 7 (2) ◽  
pp. 40-51
Author(s):  
Liudmyla Grishchenko ◽  
Tetiana Bezugla ◽  
Anna Vakaliuk ◽  
Alexander Zaderko ◽  
Оleksandr Mischanchuk ◽  
...  

We proposed the brominated carbon cloth that made of polyacrylonitrile-based activated carbon fibers (PAN-ACFs) as a precursor to chemically and uniformly graft SO3H groups to prepare the solid acid catalyst. The thermal and catalytic properties of the sulfonated PAN-ACFs were examined by IR controlled catalytic measurements and thermal analysis. The catalytic test results showed that the sulfonated surface remarkably improved the operating efficiency in isopropanol dehydration by decreasing the reaction temperature. All PAN-ACFs with grafted SO3H groups prepared through brominated precursors can converse 100% of isopropanol into propylene at moderate temperature. They showed the highest catalytic activity compared to PAN-ACFs sulfonated with oleum and chlorosulfonic acid, which conversed only 40% and 70% of isopropanol into propylene and deactivated at the higher temperatures in the reaction medium.

2018 ◽  
Vol 16 (1) ◽  
pp. 923-929 ◽  
Author(s):  
Sezer Erdem ◽  
Beyhan Erdem ◽  
Ramis Mustafa Öksüzoğlu

AbstractIn our approach for magnetic iron oxide nanoparticles surface modification, the fabrication of an inorganic shell, consisting of silica by the deposition of preformed colloids onto the nanoparticle surface and functionalization of these particles, was realized. The magnetic nanoparticles, non-coated and coated with silica layer by Stöber method, are functionalized with chlorosulfonic acid. The magnetic nanoparticles (MNPs), in size of 10-13 nm, could be used as acid catalyst in biodiesel production and show superparamagnetic character. The prepared nanoparticles were characterized by different methods including XRD, EDX, FT-IR and VSM. The catalytic activity of the coated and non-coated solid acids was examined in palmitic acid-methanol esterification as an industrial reaction for biodiesel synthesis. Although thin silica layer results in only a minor obstacle with respect to magnetism, it can accelerate the mass transportation due to its relatively porous structure and magnetic core may be more stable in the acidic reaction medium by means of covering process. Accordingly, coating strategy can be efficient way for allowing applications of MNPs in acid catalyzed esterification.


Author(s):  
Charishma Venkata Sai Anne ◽  
Karthikeyan S. ◽  
Arun C.

Background: Waste biomass derived reusable heterogeneous acid based catalysts are more suitable to overcome the problems associated with homogeneous catalysts. The use of agricultural biomass as catalyst for transesterification process is more economical and it reduces the overall production cost of biodiesel. The identification of an appropriate suitable catalyst for effective transesterification will be a landmark in biofuel sector Objective: In the present investigation, waste wood biomass was used to prepare a low cost sulfonated solid acid catalyst for the production of biodiesel using waste cooking oil. Methods: The pretreated wood biomass was first calcined then sulfonated with H2SO4. The catalyst was characterized by various analyses such as, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The central composite design (CCD) based response surface methodology (RSM) was applied to study the influence of individual process variables such as temperature, catalyst load, methanol to oil molar ration and reaction time on biodiesel yield. Results: The obtained optimized conditions are as follows: temperature (165 ˚C), catalyst loading (1.625 wt%), methanol to oil molar ratio (15:1) and reaction time (143 min) with a maximum biodiesel yield of 95 %. The Gas chromatographymass spectrometry (GC-MS) analysis of biodiesel produced from waste cooking oil was showed that it has a mixture of both monounsaturated and saturated methyl esters. Conclusion: Thus the waste wood biomass derived heterogeneous catalyst for the transesterification process of waste cooking oil can be applied for sustainable biodiesel production by adding an additional value for the waste materials and also eliminating the disposable problem of waste oils.


RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14071-14078
Author(s):  
Xi-Que Wu ◽  
Pan-Dao Liu ◽  
Qun Liu ◽  
Shu-Ying Xu ◽  
Yu-Cang Zhang ◽  
...  

A new strategy was developed to produce cellulose nanofibrils and films from elephant grass using deep eutectic solvents and a recyclable solid acid catalyst with assistance of ultrasonic disintegration and a suction filtration film forming method.


2021 ◽  
Author(s):  
Manickam Selvaraj ◽  
Mohammed A. Assiri ◽  
Hari Singh ◽  
Jimmy Nelson Appaturi ◽  
Subrahmanyam Ch ◽  
...  

Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for synthesis of 4-phenyl-1,3-dioxane (4-PDO) under a liquid phase heterogeneous catalytic method. For comparison study, the...


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Davide Rigo ◽  
Nadia Alessandra Carmo Dos Santos ◽  
Alvise Perosa ◽  
Maurizio Selva

An unprecedented two-step sequence was designed by combining batch and continuous flow (CF) protocols for the upgrading of two aminodiol regioisomers derived from glycerol, i.e., 3-amino-1,2-propanediol and 2-amino-1,3-propanediol (serinol). Under batch conditions, at 80–90 °C, both substrates were quantitatively converted into the corresponding amides through a catalyst-free N-acetylation reaction mediated by an innocuous enol ester as isopropenyl acetate (iPAc). Thereafter, at 30–100 °C and 1–10 atm, the amide derivatives underwent a selective CF-acetalisation in the presence of acetone and a solid acid catalyst, to afford the double-functionalized (amide-acetal) products.


2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Lindsey A Welch

AbstractGreen chemistry and sustainability are important concepts to incorporate into the undergraduate chemistry curriculum. Through the development of innovative undergraduate chemistry research projects in these areas, retention of students in the physical sciences can be improved. This paper describes two projects in undergraduate catalysis research: hydrogenation of furfural and the esterification of biooil from pyrolyzed wood. Catalytic transfer hydrogenation (CTH) of furfural with Pd/C led to the production of furfuryl alcohol, furfuryl isopropyl ether, 2-methylfuran, and tetrahydrofurfuryl alcohol. The metal chloride additives improved selectivity for furfuryl alcohol and furfuryl isopropyl ether. Catalytic conversion of pyrolyzed wood biooil in ethanol with a solid acid catalyst yielded ethyl esters, including ethyl acetate and ethyl propionate, as characterized by GC/MS These projects are described in the context of engaging undergraduate students in hands-on research for the purpose of improving retention and persistence, as well as preparing young scientists to enter graduate programs and the STEM workforce.


ACS Omega ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 3875-3883
Author(s):  
Yixuan Huang ◽  
Guangcai Zhang ◽  
Qinhui Zhang

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 437 ◽  
Author(s):  
Ralentri Pertiwi ◽  
Ryan Oozeerally ◽  
David L. Burnett ◽  
Thomas W. Chamberlain ◽  
Nikolay Cherkasov ◽  
...  

The metal–organic framework MIL-101(Cr) is known as a solid–acid catalyst for the solution conversion of biomass-derived glucose to 5-hydroxymethyl furfural (5-HMF). We study the substitution of Cr3+ by Fe3+ and Sc3+ in the MIL-101 structure in order to prepare more environmentally benign catalysts. MIL-101(Fe) can be prepared, and the inclusion of Sc is possible at low levels (10% of Fe replaced). On extended synthesis times the polymorphic MIL-88B structure instead forms.Increasing the amount of Sc also only yields MIL-88B, even at short crystallisation times. The MIL-88B structure is unstable under hydrothermal conditions, but in dimethylsulfoxide solvent, it provides 5-HMF from glucose as the major product. The optimum material is a bimetallic (Fe,Sc) form of MIL-88B, which provides ~70% conversion of glucose with 35% selectivity towards 5-HMF after 3 hours at 140 °C: this offers high conversion compared to other heterogeneous catalysts reported in the same solvent.


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