Sulfonic Acid Catalyst Research Articles

Sulfonic acid functionalized SBA−15 catalyst and mercaptopropionic acid promotor for the selective synthesis of p,p′−bisphenol A: Replacement to mineral acid−based process

The significance of selective catalysis in producing plastic monomers is crucial to meet sustainability and economic requirements. It is essential to develop a selective solid acid catalyst to replace irrecoverable corrosive mineral acids and thermolabile sulfonated resins for the production of p,p′−bisphenol A (BPA) isomer, a key intermediate in polycarbonate production. However, limited success has been achieved due to low activity and selectivity towards the desired p,p′−BPA isomer. Herein, a mild and selective route is presented for producing p,p′−BPA using SBA-15 functionalized sulfonic acid catalysts. Sulfonic acid-based catalysts with and without alkyl chain linkers, supported on SBA−15, were synthesized to evaluate the effect of acidity, and textual properties on the catalytic efficiency, and product selectivity. Among all the synthesized catalysts, SBA−15−Pr−SO3H exhibited the highest product selectivity. The addition of mercaptopropionic acid (as a promoter) enhanced the catalytic efficiency and afforded ∼99% acetone conversion, with 97.3% p,p′−BPA selectivity. A detailed mechanism with and without the promoter is proposed. The study also highlights the potential of mesoporous SBA−15−supported sulfonic acid catalysts as a selective and efficient catalyst for synthesizing bisphenol derivatives from the lignocellulose biomass−derived platform molecules, addressing challenges posed by fossil resources.

Conversion of chicory to valuable chemical LA and by-products with LABSA and BSA

This work examined the hydrothermal breakdown of biomass to platform chemicals, including acetic acid (AA), formic acid (FA), 5-hydroxy methylfurfural (5-HMF), and levulinic acid (LA). Chicory was selected as feedstock bacause of high potential to produce . Reactions were performed with BSA (Benzenesulfonic acid) and LABSA (Linear alkyl benzene sulfonic acid) as sulfonic acid catalysts. The studies were conducted with different catalyst concentrations (100, 300, and 600 mM) for 110 minutes at 200 °C with a biomass to solvent ratio of 1g/25 mL. The variation of product yield and composition on parameters such as time, sulfonic acid concentration and type were investigated. The maximum levulinic acid yields (wt.%) achieved through the experiments of this study were 23.95 wt.% (9.58 g/L) for 600 mM BSA and 85.93 wt.% (34.37 g/L) for 600 mM LABSA at 200 °C. Highest carbon-based yields of levulinic acid were obtained with 300 mM LABSA and 100 mM BSA.

Hal-Py-SO3H as a novel and recyclable catalyst for highly efficient synthesis of xanthene and spiropyran derivatives

The aim of this research is to synthesize a new sulfonic acid catalyst based on halloysite nanotubes (Hal-Py-SO3H) and characterize it as a solid acid nanocatalyst by various analytical techniques such as Fourier-Transformed Infrared spectroscopy (FTIR), Thermal gravimetric Analysis (TGA), X-ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), Vibrating Energy-Dispersive X-ray analysis (EDX), Transmission electron microscopy (TEM) and X-ray atomic mapping. Furthermore, this new catalyst was evaluated in synthesizing spiropyran derivatives via multicomponent reactions (MCRs) and Xanthen derivatives under environmentally sustainable conditions. The main advantages of this approach include green conditions, excellent yields, quick reaction rates, and ease of preparation. Additionally it was observed that the catalyst exhibited robust stability even after multiple recycling processes, indicating its potential for practical applications in sustainable chemical transformations.

Three components: one-pot synthesis of tetrazoles using silica-supported melamine tri-sulfonic acid, an efficient and reusable heterogeneous catalyst

The effective and straightforward procedure for synthesizing 1-H 1,2,3,4 tetrazole involves the reaction of a primary amine, triethyl orthoformate and sodium azide in the presence of silica-supported melamine tri sulfonic acid. One pot synthesis of tetrazole derivatives over the silica-supported melamine tri sulfonic acid catalyst reveals that the existence of strong acid sites in silica makes it more efficient with respect to the shortening of the reaction time (5–6 h) and excellent yield (75-84%) as compared to the other catalysts. This process includes benefits like a more environmentally friendly path, an easier work-up, a reusable catalyst and a high yield.

Chemoselective direct amidation of fatty acids with furfurylamine without coupling reagents in reversed micellar microenvironment

AbstractFuran heterocyclic compounds derived from renewable sources are popular versatile candidates for the production of multifunctional macromolecular materials. These compounds are also used as hydrophobilization monomers for reversible polyadducts or as versatile building blocks in Diels‐Alder reactions. In the present study, an efficient approach to chemoselective acylation of furfurylamine with a series of non‐preactivated monocarboxylic or dicarboxylic long‐chain fatty acids and some of their functionalized derivatives has been achieved via catalytic direct amidation in reversed micellar medium. A convenient and environmentally friendly method has been developed for furfurylamides via a dehydrative coupling reaction. For this purpose, a new cationic Brønsted‐type sulfonic acid catalyst containing a hexadecyl alkyl chain was synthesized and fully characterized. The present catalytic reaction produced the respective N‐furfurylamides materials in good to excellent yields. This study also confirms that the direct amidation of carboxylic acids with selected amine compounds can be successfully catalyzed by Brønsted acids. Its simplicity and high atom economy are the main advantages of this method.

The effect of vacuum process on biodiesel production from Palm Kernel Fatty Acid Distillate

This study examines the operating pressure effect on the manufacture of biodiesel from Palm Kernel Fatty Acid Distillate (PKFAD) by using para-Toluene Sulfonic Acid (PTSA) catalyst. The operating pressures studied are the vacuum pressures of 70 kPa, 80 kPa, 90 kPa, and 100 kPa, which varied with PTSA concentrations of 5%, 10%, 15%, 20%, and 25%, and the molar ratios of methanol and PKFAD are 5:1, 6:1, 7:1, 8:1, 9:1, and 10:1. Biodiesel production from PKFAD was carried out with reaction duration of 120 minutes and reaction temperature at 50 0C. The amounts of fatty acids converted to biodiesel were calculated based on the initial and acid numbers after the esterification reaction. The results show that a vacuum pressure of 70 kPa to 100 kPa provides a conversion above 96% for all catalyst concentrations and all methanol and PKFAD molar ratios. The highest conversion of PKFAD to biodiesel of 98.6% is obtained at an operating pressure of 80 kPa, a catalyst concentration of 25%, and the molar ratio of methanol and PKFAD is 10:1. The biodiesel characteristics obtained in this study have met the standards of the American Society for Testing Materials.

Silica-pyridine sulfonic acid catalyst for cellulose and glucose hydrolysis

An innovative catalyst was developed for the purpose of simplifying the manufacturing process of biofuels without the need for costly materials. The incorporation of pyridine sulfonic acid (PSA) into silica rice husk (RH) was achieved by two distinct strategies, resulting in the production of a heterogeneous catalyst. The first catalyst, RHAPSA@Dir, was prepared using the Sol-Gel technique through a one-pot synthesis approach. The second catalyst, RHAPSA@Ref, was created through post-synthesis means. BET analysis of RHAPSA@Dir showed a significant improvement in surface area to 416 m2/g, while RHAPSA@Ref only exhibited 48.2 m2/g. Upon conducting elemental research on both catalysts, it was observed that the presence of carbon, nitrogen, and sulfur was apparent. The thermal study conducted indicated that approximately 47–48% of organic matter was lost from the silica at the anticipated temperature. The SEM analysis of RHAPSA@Dir revealed that a minor level of pore arrangement was observed. Furthermore, the TEM analysis of RHAPSA@Dir demonstrated that a few particles exhibited spherical nano shapes that were clearly visible. Conversely, the SEM analysis of RHAPSA@Ref showed a rough and porous surface with large particles. Lastly, the TEM micrograph of RHAPSA@Ref revealed spherical particles with an approximate diameter of 6 nm. The use of electron microscopy revealed the presence of spherical nanostructures. Both cellulose and glucose underwent hydrolyzation over the catalysts within 2–6 h at 140 °C. The essential properties of both catalysts were their stability and reusability.

Sulfonic acid catalysts derived from lignosulfonates

Sulfonic acid catalysts derived from lignosulfonates

Synthesis, Biological Evaluation, Molecular Docking and Kinetic Investigation of New 2,4,5‐Trisubstituted Imidazole Derivatives as Antidiabetic Agents

AbstractA series of novel 2,4,5‐trisubstituted imidazole motifs have been synthesized by a magnetically‐tuned halloysite‐supported sulfonic acid catalyst. The prepared supported sulfonic acid catalyst was well characterized by High‐resolution transmission electron microscopy (HR‐TEM), Scanning electron microscopy (SEM), Energy dispersive X‐rays spectroscopy (EDS), Fourier transform infrared (FTIR), X‐ray powder diffraction (XRD), Thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and Vibrating–sample magnetometry (VSM) techniques; and compounds were confirmed by 1H, 13C‐Nuclear magnetic resonance (NMR) and High resolution mass spectrometry (HRMS) techniques. The purity of compounds was established by High performance liquid chromatography (HPLC). All the prepared compounds were screened for their in vitro antidiabetic activity by using α‐amylase and α‐glucosidase inhibition assay taking acarbose as a reference standard and were found to exhibit significant α‐amylase inhibitory potentials, whereas for α‐glucosidase inhibition, compounds were equipotent to the reference standard. Compound bearing ferrocene moiety was identified as the strongest α‐amylase inhibitor of the series with IC50=47.83±0.63 μM, a five‐fold more potency compared to acarbose (IC50 =269.39±0.29 μM). The presence of substituents in the second position of imidazole pharmacophore plays a key role in inhibitory activity. To find the possible binding interaction of compounds, in silico molecular docking study was performed.

Design approach for the sustainable synthesis of sulfonated biomass-derived hydrochars and pyrochars for the production of 5-(hydroxymethyl)furfural

The sustainable synthesis of carbon-based sulfonated acid catalysts from biomass is of paramount importance from the perspective of sustainability. However, the traditional pyrolysis method leads to low solid yields and poor carbon stability. A cascade synthesis is here proposed, combining hydrothermal carbonization and pyrolysis, to produce a “high-quality” carbon-based precursor, followed by its sulfonation to increase the pristine acidity. The proposed multi-step preparation is effective when each step is optimized, primarily the hydrothermal carbonization, which should be carefully optimized. A chemometric approach was employed to optimize the hydrochar synthesis, using microcrystalline cellulose as starting feedstock. The identified optimal reaction conditions were applied to the hydrothermal carbonization of hazelnut shells, which is a more complex but cheaper feedstock, and the obtained hydrochars were pyrolyzed to produce pyrochars. The most promising chars were sulfonated and tested as heterogeneous acid catalysts in the aqueous conversion of fructose to 5-(hydroxymethyl)furfural, a promising platform chemical of great industrial interest, obtaining maximum yields of about 40 mol%. These promising results pave the way for the use of such wastes as efficient acid catalysts for the synthesis of 5-(hydroxymethyl)furfural, contributing to ensure the biomass circular exploitation.

Sulfonic acid-type hydrothermal carbon microspheres as stable, efficient catalysts for transesterification reactions

With the aim of preparing a sulfonic acid-type solid acid catalyst having a high density of acid sites and excellent stability, this work synthesized sulfonic acid bowl-shaped hydrothermal carbon microspheres (SA-OBHCs), using amine groups as the primary sulfonic acid bonding sites. This material was synthesized via a three-step functionalization process comprising the oxidation, amidation and sulfonation of BHCs. The extent to which chlorosulfonic acid reacted with amine groups in diethylenetriamine molecules on microsphere surfaces was also investigated using density functional theory calculations. These calculations showed that the substitution reaction of primary amines proceeded less readily than that of secondary amines but provided a more stable product. The surface acid density of the SA-OBHCs was as high as 11.2 mmol·g−1 and the –SO3H groups on the SA-OBHCs were found to be thermally stable up to 200 °C. These SA-OBHCs were subsequently used to catalyze the synthesis of fatty acid methyl esters (FAMEs) from a waste frying oil model compound and methanol. Reactions performed using a methanol/oil molar ratio of 20:1 at 140 °C for 3 h gave a FAMEs yield of 93.4 %. After four reuses, an SA-OBHCs specimen provided a FAMEs yield of 77.5 %, demonstrating the significant stability of this material.

Glycerol based carbon sulfonic acid catalyzed synthesis, in silico studies and in vitro biological evaluation of isonicotinohydrazide derivatives as potent antimicrobial and anti-tubercular agents

The present pathway involves synthesis of isonicotinohydrazide derivatives using isoniazid and diversely substituted aldehydes in the presence of EtOH and catalytic amount of glycerol based carbon sulfonic acid catalyst. The developed pathway has so many merits like excellent yields (91–98%), short reaction time (4–10 min), easy reaction set up, no need of column chromatography, large substrate scope, easily recyclable and reusable catalyst. The synthesized compounds were screened for antimicrobial and anti-tubercular activity and it was observed that compounds possessed high biological potency against the Gram positive and Gram negative bacterial and fungal strains. Regarding anti-tubercular activity, compound 3m exhibited high % inhibition against Mycobacterium tuberculosis H37RV strain. Based on the outcome of in vitro studies, all the synthesized compounds were docked against E. coli (1KZN), C. albicans (1IYL), and M. tuberculosis H37Rv strain (2NSD). The synthesized derivatives were docked within the binding site of 1KZN, and 1IYL. However, with 2NSD, apart from 3h, all the derivatives displayed interaction within the binding cavity of the protein. All the crucial interactions with Asn46, Asp73, and Arg136 in 1KZN, His227, Leu451 in 1IYL, and Tyr158 in 2NSD were witnessed in the top-scored docked candidates. Molecular docking studies revealed the importance of the substitution at R position on isonicotinohydrazide scaffold. The nitrogen atoms of hydrazide moiety were involved in forming hydrogen bonding with the active site amino acids, and the substitution at the R position occupy the hydrophobic position in the binding pocket. Also, the functional groups present on the substituted R position were involved in forming hydrogen bonding with the crucial active site residues.

Control of selectivity in the preparation of 2-substituted benzoazoles by adjusting the surface hydrophobicity in two solid-based sulfonic acid catalysts.

A series of metal-free tandem reactions for the synthesis of pharmaceutically important 2-substituted benzoazoles from isothiocyanates and 2-aminothiophenol under catalyst-free conditions in the presence of Et-PMO-Me-PrSO3H (1a) and SBA-15-PrSO3H (1b) as solid acids were carried out in a highly selective way under solvent free conditions. A significant selectivity changeover toward either 2-mercaptobenzoxazole or 2-aminobenzoazole derivatives could be achieved by changing the employed catalyst from the relatively hydrophobic material 1a to the more hydrophilic catalyst 1b. This simple experimental procedure with a novel selective approach toward benzoazoles accompanied by green and reusable catalysts could be considered as an alternative to the existing methods for the synthesis of 2-substituted benzoazole derivatives.

Development and Application of a Supramolecular Brønsted Acid Catalyst Based on the Noria Macrocycle.

The synthesis of derivatives of the Noria macrocycle and the structurally similar macrocycle, R3, each containing 12 sulfonic acid groups, is reported. Herein, we demonstrate their utility as reusable Brønsted acid catalysts for the Biginelli synthesis of dihydropyrimidinones and the Pechmann synthesis of coumarins. We also demonstrate that the supramolecular structure directs the reagents to interact with the sulfonic acid catalytic sites, thus increasing the catalyst's efficiency compared to other monomeric, macrocyclic, and polymeric sulfonic acid catalysts.

Recent Developments in the Applications of Biomass‐Derived Sulfonated Carbonaceous Solid Acid Catalysts

AbstractRecently, carbon‐based materials are gaining a lot of attraction. It is considered as an emerging area of research and has gained significant importance as an efficient catalyst/material in various fields. Biomass is abundantly available, cheap and a renewable carbon resource. Sulfonated carbonaceous solid acid catalyst can be derived by sulfonation of various sources of biomass such as sugars, lignin, fruit waste, agro‐waste, bio‐char, etc. Sulfonated carbonaceous solid acid catalysts can be used as a substitute to liquid acids. These catalysts possess a stable carbon skeleton and are insoluble in almost all organic solvents as well as under acidic/basic conditions. This review covers details about biomass‐derived sulfonated carbonaceous solid acid catalysts and its catalytic activities in many important transformations such as hydrolysis of cellulose, synthesis of biodiesel, synthesis of various important chemicals and for various organic transformations.

Synthesize, characterization and application of a novel three-dimensional magnetic graphene oxide decorated with polyester dendrimers for detection of donepezil hydrochloride in pharmaceutical formulation and biological fluid

This research was conducted to develop a novel adsorbent based on hyperbranched polyester dendrimers for selective determination and separation of donepezil hydrochloride. In this paper, different generations of hyperbranched polyester dendrimers were grafted onto graphene oxide. New types of carboxyl-terminated hyperbranched polyesters with aromatic-aliphatic structure were synthesized using the direct esterification reaction between succinic acid and phloroglucinol in the presence of p-toluene sulfonic acid catalysts. The 5th generation of polyester dendrimers was modified by p-aminohippuric acid to enhance its adsorption capacity and improve dendrimer biocompatibility. The hyperbranched polyester dendrimers with magnetic nanoparticles were obtained through vacuum freeze-drying process and was used in a new method for the preparation of three-dimensional/ graphene oxide-grafted hyperbranched polyester dendrimers. The synthesized nanoparticles were investigated using Fourier-transform infrared spectrometry, X-ray diffraction, field-emission scanning electron microscopy equipped with energy-dispersive spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller, thermal gravimetric analysis and vibrating sample magnetometry. The effective experimental parameters were optimized. Adsorption of donepezil hydrochloride by nanoadsorbent can be best described by a Langmuir isotherm with a high correlation coefficient. The three-dimensional/ graphene oxide -grafted hyperbranched polyester dendrimers were applied for extraction of donepezil hydrochloride from biological and pharmaceutical samples through high-performance liquid chromatography-ultraviolet technique.

An Efficient Synthesis of 3,4-dihydro-2(1H)-pyrimidinones from Aldehyde Bisulfite Adducts using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

Abstract: An efficient one-pot multicomponent synthesis of 3,4- dihydropyrimidin-2(1H)-ones has been developed from aldehyde bisulfite adducts, ethyl acetoacetate and urea using recyclable polymer- supported sulfonic acid catalyst. This new method provides several advantages over the previous synthesis, including high product yields, commercially viable, minimal workup operations and sustainable chemical practices.

Aryl sulfonic acid catalysts: Effect of pendant group structure on activity in hydrolysis of polyethylene terephthalate

AbstractA series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface of poly(ethylene) terephthalate (PET) particles. Specifically, p‐toluenesulfonic acid monohydrate (PTSA), 2‐naphthalenesulfonic acid (2‐NSA), and 1,5‐naphthalenedisulfonic acid tetrahydrate (1,5‐NDSA) were chosen to provide sulfonic acid active groups and varying hydrophobic functionality. The effect of catalyst concentration and reaction temperature on PET hydrolysis rate was studied. The aryl sulfonic acid catalysts exhibited much higher rates of PET hydrolysis than the mineral acid, H2SO4. At 150°C and 4 M catalyst, the time required to achieve more than 90% TPA yield was 3, 3, and 8 h, and 18 h for (PTSA), (2‐NSA), (1,5‐NDSA), and H2SO4, respectively. Ethyl acetate hydrolysis was performed as a model reaction to probe the activity of the catalysts in homogenous reactions to compare with the heterogenous hydrolysis reaction occurring at the PET surface. The higher catalytic activities for PET hydrolysis of the PTSA, 2‐NSA, and 1,5‐NDSA than H2SO4 was attributed to improved wetting by the reaction media and affinity of the aryl sulfonic acid catalysts for the PET surface.

Synthesis of a KIT-6 mesoporous sulfonic acid catalyst to produce biodiesel from cashew nut oil

Synthesis of a KIT-6 mesoporous sulfonic acid catalyst to produce biodiesel from cashew nut oil

Kinetic Study of Methanol Dehydration to Dimethyl Ether in Catalytic Packed Bed Reactor over Resin

Dimethyl ether (DME) is considered as a significant fuel alternative with a critical manufacturing process. Only a few authors have presented the kinetic analysis of attractive and alternative catalysts to Al2O3 and/or zeolite in DME production, despite the fact that there is a large library of kinetic studies for these commercial catalysts. The purpose of this research was to contribute to this direction by conducting a catalytic test to determine kinetic parameters for methanol dehydration over sulfonic acid catalysts (resin). However, due to the relevance of the mathematical description of this process in the industry was also studied, a study of kinetics parameters and mathematical modeling of methanol dehydration in an atmospheric gas phase in a fixed bed reactor with a temperature range (90&degC - 120&degC) was examined. The Langmuir-Hinshelwood (L-H) model provides the best fit to experimental data, with an excellent R2 = 0.9997, and the experimental results were compared to those predicted by these models with very small deviations. The kinetic parameters were found to be in good agreement with the Arrhenius equation, with acceptable straight-line graphs. The activation energy E was computed and found to be 27.66 kJ/mole, with an average variation of 0.32 percent between the predicted and calculated results. Simple mathematical continuum models (plug flow reactor PFR) showed an acceptable agreement with the experimental data.