Supported Ionic Liquids Research Articles

Tackling water contamination by oncologic drugs: Supported ionic liquids as sustainable adsorbents for cyclophosphamide removal

Due to the increasing incidence of cancer, the consumption of highly toxic oncological drugs is continuously growing. Given the current lack of efficient technologies to remove/treat these toxic drugs in wastewater treatment plants, the environmental quality is compromised, and aquatic organisms are at risk. To address this critical environmental burden, a new strategy based on supported ionic liquids (SILs) for the simultaneous removal of oncologic drugs and toxicity reduction of aqueous samples is here proposed. Silica-based SILs functionalized with imidazolium-based and quaternary ammonium-based ILs were designed and kinetics and isotherm adsorption studies performed. Aiming to develop an adsorbent able to reduce the toxicity of aqueous samples contaminated with oncological drugs, the toxicity reduction was appraised using the model organism Danio rerio. The obtained results disclose that among the studied SILs, the [Si][N3888]Cl (silica functionalized with propyltrioctylammonium chloride) is the best adsorption material (maximum adsorption capacity, qmax = 67.64 mg g−1), with a fast adsorption rate (<20 min). Furthermore, [Si][N3888]Cl was able to remove the toxicity of the treated aqueous samples towards D. rerio embryos, as assessed by lethal and several sublethal endpoints, demonstrating that this material holds remarkable potential for oncological drugs pollution remediation.

Supported ionic liquids to purify microbial L-Asparaginase

L-Asparaginase (ASNase) is a versatile enzyme that converts L-asparagine into ammonia and aspartic acid. This enzyme has applications in the food industry and health sector. However, high purity ASNase is required, resulting in high production costs. Therefore, in this work, two supported ionic liquids (SILs), specifically silica modified with dimethylbutylpropylammonium chloride ([Si][N3114]Cl) or triethylpropylammonium chloride ([Si][N3222]Cl), were investigated as alternative adsorption materials to purify ASNase. Different conditions were evaluated to improve enzyme purity, including total protein content in the cell extract, contact time, and SIL/cell extract ratio (w/v). Under optimal conditions using [Si][N3114]Cl, a maximum ASNase purification of 6.1-fold is achieved in a single step, resulting from the preferential attachment of other proteins on [Si][N3114]Cl SIL. According to the results, hydrophobic interactions rule the selective adsorption of protein impurities from the cell extract by the SIL, thereby increasing the ASNase purification levels. This approach offers a significant advantage, not requiring the desorption and elution of the target enzyme, while envisioning the application of SILs in a flow-through elution approach. The protonation state of protein surface was calculated by computational analysis, revealing that positively charged amino acids such as arginine and lysine block the effective binding of the enzyme to the SILs. Overall, if properly designed, SILs are promising alternative supports for the downstream processing of ASNase from cell extracts.

One-pot synthesis of cyclic carbonates from olefins and CO2 catalyzed by silica-supported imidazolium hydrogen carbonate ionic liquids

The direct synthesis of cyclic carbonates by catalytic oxidative carboxylation of olefins with CO2 has become an essential topic, but the development of highly active metal- and halogen-free heterogeneous single catalysts is still a huge challenge. Herein, a series of [Im][HCO3]@SBA-15 supported ionic liquids (SILs) catalysts are prepared by using anion exchange and solvent-free mehcanochemical grafting strategies for the direct synthesis of cyclic carbonates from olefins and CO2. As-prepared [Im][HCO3]@SBA-15 catalysts exhibit excellent catalytic activity and selectivity for the one-pot synthesis of cyclic carbonates from various olefins and CO2 under metal- and halogen-free conditions, providing moderate to excellent yields of cyclic carbonates. Furthermore, the catalysts can be easily regenerated at least five times without significant loss of catalytic activity, exhibiting excellent reusability and stability. This work presents an efficient and green method for the design and preparation of SILs catalysts for CO2 conversion.

SBA-15 Supported Benzimidazolium-based Ionic Liquids: Synthesis, Characterization, and Applications in the Fuel Desulfurization

SBA-15 supported benzimidazolium-based ionic liquid ([email protected][BzIm][Cl]) has been synthesized with immobilization of trimethoxysilane-modified 1-methylbenzimidazolium chloride ([BzIm][Cl]) onto synthesized SBA-15 silica support material. SBA-15 and [email protected][BzIm][Cl] were characterized using FTIR, SEM, TEM, EDS, SAXS, BET, and NMR spectroscopy. The variation was found in the morphology as well as structure of [email protected][BzIm][Cl] with variation in the content of [BzIm][Cl]. The application of synthesized SBA-15 supported [BzIm][Cl] was studied for the removal of sulfur compounds from model fuel and real gasoline samples. It was found that in contrast to pure SBA-15, supported ionic liquids (SILs) showed higher efficiency for the adsorption of different sulfur-containing aromatic heterocyclic compounds from model fuel. Similarly, SIL having large IL content was found more efficient in the removal of sulfurous compounds from model and real gasoline samples in comparison to SIL having lesser IL content. Moreover, the adsorbents were reused 10 times without any significant loss in adsorption efficiency.

Ordered mesoporous silica matrices supported ionic liquids for efficient CO2 separation from CO2/CH4 gas mixture: Experimental and theoretical investigation

Global concern over CO2 reduction to avoid global warming has escalated due to alarming CO2 concentrations in the atmosphere. In this connection, supported-ionic liquids (SILs) have been prepared by physically imbibition of 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mim BF4) ionic liquid (IL) into ordered mesoporous silica (MS) matrices to design SILs-membranes (SILMs) for gas separation technology. These SILs were characterized by powder XRD, 29Si NMR, SEM, FTIR, and 1H NMR spectroscopy, N2 sorption, and TGA analyses. FTIR study reveals that vibrational frequencies related to C2mim+ cation ring remain unchanged upon confinement of nanopores of MS whereas Si-O-Si band, Si-O band, and anion band shifted indicating IL interacting with the MS surfaces. Density functional theory (DFT) calculations also explore the structural features of these SILs. SILMs based on Pebax-1657 were also designed using a solution casting technique to evaluate their gas separation performance and characterized using XRD and SEM techniques. C2mimBF4/MCM-48 membrane exhibit higher permeability for CO2 both in single and mixed gas studies. These results were further supported by DFT analysis in terms of complexation energies (Ec) which demonstrates the strong affinity of these SILs membranes towards CO2 and CH4 gases, respectively. Further, a nice correlation was established between the experimental and theoretical findings.

MCM-41 supported S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ionic liquids: synthesis, characterization, and application in the fuel desulfurization

Supported ionic liquids (SILs), synthesized by immobilization of ionic liquids (ILs) onto solid support materials, have played an effective role in several applications like fuel desulfurization, organic catalysis, gas separations, biofuel synthesis, etc., in comparison to pure ILs which suffer from many drawbacks like difficult recovery, high cost, mass transfer issue owing to large viscosity, toxic nature, complications in product purifications and fixed bed reactor technology. In this study, a series of new SILs (MCM-41@[S-RBTh][Cl]; R = aryl/alkyl groups) were synthesized via immobilization of different S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ILs onto MCM-41 silica support. Structure elucidation of SILs was achieved through SEM, EDS, SAXS, NMR, BET, and FT-IR spectroscopy. Further, the synthesized SILs and MCM-41 were investigated for the removal of sulfur-containing aromatic species from model gasoline and real gasoline. MCM-41@[S-BzBTh][Cl] (0.5 g) removed maximum sulfur content with the percentage of 57.5 % (at 35 °C), 58.7 % (at 40 °C), and 63.4 % (at 45 °C) of TS, TN, and DBT respectively, from model gasoline (5 g) of sulfur concentration of 200 ppm under shaking conditions for 140 min. The impact of the aryl group and different lengths of alkyl groups of supported benzothiazolium-based ILs on their adsorption performance was also studied.

An efficient initiator system containing AlCl3 and supported ionic-liquid for the synthesis of conventional grade polyisobutylene in mild conditions

Ionic liquid based systems are used to facilitate the cationic polymerization of isobutylene to conventional grade polyisobutylene (PIB) using AlCl3 as an initiator. Specifically, the compound 1-butyl-3-methylimidazolium chloride (IL) is employed as a reference system due to its simplicity, as well as the polyionic liquid (PIL), prepared via radical polymerization of 1-butyl-3-vinylimidazolium chloride, and the halloysite clay (Hal) supported ionic liquid (S-IL). The overall results stated that the designed AlCl3/S-IL initiator system can be used as a safer and greener alternative to the industrially used BF3 system, in the development of isobutylene polymerizations under mild reaction conditions to conventional grade PIB for viscosity improvement applications. The microstructure and final properties of the as-synthesized PIB was unraveled and compared to Indopole 2100, as a commercial PIB. DFT calculations were performed to understand the different performance of IL and PIL with respect to the S-IL system, and also to show why the catalyst loading for the latter system is lower, as well as to understand how each of the three systems sequesters the catalyst AlCl3. Since the interaction is non-covalent or ionic, in addition to NBO charges, NCI plots were also used.

SBA-15 supported benzoxazolium-based ionic liquids: Synthesis, characterization, and application in the adsorptive desulfurization

In this study, organosilane-modified S-aryl/alkyl-substituted benzoxazolium-based ionic liquids ([S-RBOx][Cl]; R = benzyl or methyl) were synthesized and immobilized on SBA-15 silica support to afford supported ionic liquids (SILs). The structure elucidation of SILs was done by using SEM, SAXS, BET, TEM, EDS, and NMR spectroscopy. Moreover, the adsorbent role of SILs and SBA-15 was studied in the adsorptive desulfurization by taking model and real gasoline samples. In contrast to SBA-15, both SIL adsorbents were found more efficient because of the π-π interactions, induced between supported [S-RBOx][Cl] and thiophene compounds. The Freundlich adsorption isotherm was found more suitable to fit the experimental adsorption data in comparison to the Langmuir isotherm. SBA-15@[S-BzBOx][Cl] was obtained with maximum adsorption capacity (328 mg/g) in comparison to SBA-15 (109.1 mg/g) and SBA-15@[S-MeBOx][Cl] (256.6 mg/g). The maximum adsorption was obtained by SBA-15@[S-BzBOx][Cl] at 45 °C within 100 min by using an adsorbent quantity of 600 mg from model gasoline having a sulfur content of 250 ppm and provided removal of TS, TN, and DBT with the percentage of 57.2%, 63.6%, and 78.9% respectively. All the SILs were reused ten times and obtained with almost constant adsorption efficiency.

Liquid Membranes in Catalysis

: The supported ionic liquid (SIL) membranes have demonstrated huge potential for numerous applications in current separation science and catalysis. Membrane technology allows for the separation of complex mixtures of gases, vapors, liquids and /or solids below trivial conditions. Simultaneous chemical transformations can also be achieved in membranes by using catalytically active materials comprising the membrane or embedded catalysts in the custom-built membrane reactors. In the present editorial, the remarkable contribution of liquid membranes in catalysis is highlighted. Some recent applications are presented and compared with conventional methods. In addition, SILs and their applications in catalysis, catalytic membranes, and recent advances in membrane separation processes are briefly described.

High Performance of Ionic-Liquid-Based Materials to Remove Insecticides.

Neonicotinoids are systemic insecticides commonly used for pest control in agriculture and veterinary applications. Due to their widespread use, neonicotinoid insecticides (neonics) are found in different environmental compartments, including water, soils, and biota, in which their high toxicity towards non-target organisms is a matter of great concern. Given their widespread use and high toxicity, the development of strategies to remove neonics, while avoiding further environmental contamination is of high priority. In this work, ionic-liquid-based materials, comprising silica modified with tetraalkylammonium cations and the chloride anion, were explored as alternative adsorbent materials to remove four neonics insecticides, namely imidacloprid, acetamiprid, thiacloprid, and thiamethoxam, from aqueous media. These materials or supported ionic liquids (SILs) were first synthesized and chemically characterized and further applied in adsorption studies. It was found that the equilibrium concentration of the adsorbate in the solid phase decreases with the decrease in the SIL cation alkyl chain length, reinforcing the relevance of hydrophobic interactions between ionic liquids (ILs) and insecticides. The best-identified SIL for the adsorption of the studied insecticides corresponds to silica modified with propyltrioctylammonium chloride ([Si][N3888]Cl). The saturation of SILs was reached in 5 min or less, showing their fast adsorption rate towards all insecticides, in contrast with activated carbon (benchmark) that requires 40 to 60 min. The best fitting of the experimental kinetic data was achieved with the Pseudo Second-Order model, meaning that the adsorption process is controlled at the solid-liquid interface. On the other hand, the best fitting of the experimental isotherm data is given by the Freundlich isotherm model, revealing that multiple layers of insecticides onto the SIL surface may occur. The continuous removal efficiency of the best SIL ([Si][N3888]Cl) by solid-phase extraction was finally appraised, with the maximum adsorption capacity decreasing in the following sequence: imidacloprid > thiacloprid > thiamethoxam > acetamiprid. Based on real reported values, under ideal conditions, 1 g of [Si][N3888]Cl is able to treat at least 106 m3 of wastewater and water from wetland contaminated with the studied neonics. In summary, the enhanced adsorption capacity of SILs for a broad diversity of neonics was demonstrated, reinforcing the usefulness of these materials for their removal from aqueous matrices and thus contributing to preventing their introduction into the ecosystems and reducing their detrimental effects in the environment and human health.

Advances Achieved by Ionic-Liquid-Based Materials as Alternative Supports and Purification Platforms for Proteins and Enzymes.

Ionic liquids (ILs) have been applied in several fields in which enzymes and proteins play a noteworthy role, for instance in biorefinery, biotechnology, and pharmaceutical sciences, among others. Despite their use as solvents and co-solvents, their combination with materials for protein- and enzyme-based applications has raised significant attention in the past few years. Among them, significant advances were brought by supported ionic liquids (SILs), in which ILs are introduced to modify the surface and properties of materials, e.g., as ligands when covalently bond or when physiosorbed. SILs have been mainly investigated as alternative supports for enzymes in biocatalysis and as new supports in preparative liquid chromatography for the purification of high-value proteins and enzymes. In this manuscript, we provide an overview on the most relevant advances by using SILs as supports for enzymes and as purification platforms for a variety of proteins and enzymes. The interaction mechanisms occurring between proteins and SILs/ILs are highlighted, allowing the design of efficient processes involving SILs. The work developed is discussed in light of the respective development phase and innovation level of the applied technologies. Advantages and disadvantages are identified, as well as the missing links to pave their use in relevant applications.

Homogeneous and Heterogeneous Ionic Liquid System: Promising “Ideal Catalysts” for the Fixation of CO2 into Cyclic Carbonates

AbstractMassive emissions of CO2 have caused environmental problems all over the world. The fixation of CO2 into cyclic carbonates is regarded as an effective way of capturing and utilizing CO2. Ionic liquid catalysts (ILCs) have received great attention and been employed for catalyzing the above reaction in recent years due to their unique properties. However, there are still a few problems requiring solutions in order to finally find the “ideal catalyst”. Herein, we reviewed a number of recent related literature. The progresses of both homogeneous and heterogeneous ILCs were discussed to find out where we are and which directions to work on. The effects of cations and anions of ionic liquids (ILs), functional groups, reaction phase states, structures of supports, preparation methods of supported ionic liquids (SILs), and interactions between the ILs and supports were investigated systematically. Accordingly, basic principles of designing ILCs for the title reaction are summarized and directions of future investigations are highlighted.

Structural and Thermal Properties of Ethylene-Norbornene Copolymers Obtained Using Vanadium Homogeneous and SIL Catalysts.

The series of ethylene-norbornene (E-NB) copolymers was obtained using different vanadium homogeneous and supported ionic liquid (SIL) catalyst systems. The 13C and 1H NMR (carbon and proton nuclear magnetic resonance spectroscopy) together with differential scanning calorimetry (DSC) were applied to determine the composition of copolymers such as comonomer incorporation (CNB), monomer dispersity (MD), monomer reactivity ratio (re), sequence length of ethylene (le) and tetrad microblock distributions. The relation between the type of catalyst, reaction conditions and on the other hand, the copolymer microstructure, chain termination reaction analyzed by the type of unsaturation are discussed. In addition, the thermal properties of E-NB copolymers such as the melting and crystallization behavior, like also the heterogeneity of composition described by successive the self-nucleation and annealing (SSA) and the dispersity index (DI) were determined.

Preparation of choline sulfate ionic liquid supported on porous graphitic carbon nitride nanosheets by simple surface modification for enhanced catalytic properties

Supported ionic liquids (SILs) have attracted rising interest and the subject of active research in the last decades due to the diversified range of applications and yet reports on ILs is still rapidly increasing. This work reports a choline sulfate ionic liquid supported on fascinating and highly stable porous graphitic carbon nitride (g-C3N4) nanosheets as an inexpensive and an environmentally friendly reusable ionic catalyst in organic synthesis typically requiring a harmful organic solvent and highly toxic acids. g-C3N4@SO3Ch was prepared by mixing sulfonic acid functionalized graphitic carbon nitride nanosheets (g-C3N4@SO3H) with choline hydroxide or via a novel approach. The introduction of a choline sulfate could significantly enlarge specific surface areas with rich reaction sites and suppressed the recombination of sheets. This work provides a new way to improve the chemical property of g-C3N4 along with the recyclability of the ionic liquid. g-C3N4@SO3Ch (IL/g-C3N4) offers an effective, reusable, inexpensive, environmentally friendly and low-cost catalyst for the synthesis of 3,4-dihydropyrimidin-2 (1H)-ones, 2,3-dihydroquinazolin-4 (1H)-ones and bisindolylmethanes in good to excellent yields. The prepared catalyst synthesized compounds were well characterized by different techniques such as FT-IR, XRD, SEM, EDX and TGA.

Synthesis of cellulose graft ionic liquid using silanization reaction

Introduction: Ionic liquids (ILs) have attached many attentions due to their interesting physicochemical properties. However, ionic liquids have several disadvantages including high viscosity, difficult to purify, separate and recycle, and expensive. Therefore, supported ionic liquids (SIL) have been developed to overcome these problems. SIL based on cellulose material was conventionally synthesized by silanization reaction between ionic liquid trialkoxyl silane and hydroxyl groups on the surface of cellulose. However, low reactivity of cellulose hydroxyl groups causes the low efficiency of silanization reaction. With the aim to resolve these problems and improve the reactivity of cellulose silanization reaction, cellulose graft ionic liquid was synthesized and characterized.&#x0D; Methods: Cellulose graft ionic liquid (CL-IL) material was synthesized by silanization reaction. The influence of reaction condition such as IL/CL (w/w) ratio, base catalyst (NH3) and agent coupling tetraethyl orthosilicate (TEOS) on silanization reaction was investigated. The modified CL-IL materials were characterized using FT-IR, TGA, SEM. The ion exchange properties were evaluated via batch adsorption studies to evidence the efficiency of silanization reaction of cellulose.&#x0D; Results: The study indicated that adding TEOS with NH3 catalyst could significantly increase the number of imidazolium groups grafted on cellulose about 75% compared to the conventional approach. CL-IL material is an efficient anion exchange materials displaying fast kinetic adsorption and high capacity adsorption of MO up to 1.4 mmol g-1.&#x0D; Conclusion: High-efficiency of cellulose silanization was obtained by using coupling agent TEOS and base catalyst. Therefore, the silanization reaction can be used for synthesis divers of functional cellulose materials. This approach can be aimed for the design of cheaper and high-performance materials for catalysis, polymer composite and adsorption in water treatment and depollution of industrial wastewater.&#x0D;

Preparing supported ionic liquids by continuous supercritical carbon dioxide adsorption method

A new method was developed to prepare supported ionic liquids (SILs) continuously with the assist of supercritical carbon dioxide (scCO2). Two ionic liquids (ILs), 1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) and 1-Butyl-3-methylimidazolium acetate ([Bmim][Ac]), were confined into SBA-15 pores by physical adsorption. Effects of duration time, pressure, temperature, and CO2 flow on ILs loadings were investigated and controllable preparation was realized. Highest loadings of 187.30% and 122.40% for [Bmim][BF4] and [Bmim][Ac] respectively were obtained. The equilibrium time and reactor volume of this continuous method were reduced by ca. 5 times and 13 times than those in a batch method. Pore structures of SILs were studied and proved to be kept perfectly by TEM and N2-sorption analysis. Ordered mesoporous structure was retained without severe blockage. The onset decomposed temperature of [Bmim][BF4] and [Bmim][Ac] measured by TGA was 280 °C and 160 °C after confinement. Only a little reduction of 10 °C happened compared with bulk ILs, suggesting the high thermal stability of SILs. FR-IR tests showed that vibration bands of imidazolium ring and [BF4] shifted after confinement due to the interaction with SBA-15.

Investigation of CO2 capture using acetate-based ionic liquids incorporated into exceptionally porous metal–organic frameworks

The potential advantage of using supported ionic liquids (SILs) for CO2 capture applications has been investigated in this work. The impregnation of 1-ethyl-3-methylimidazolium Acetate [emim][Ac] into two voluminous metal–organic frameworks (MOF-177 and MIL-101) is evaluated using different synthesis methods. The performance of the composite sorbents for CO2 capture has been evaluated using various characterization techniques. The successful incorporation of [emim][Ac] into the pores of MOF-177 and MIL-101 have been confirmed using thermogravimetric analysis and Fourier transform infrared spectroscopy results. Furthermore, the porosity of the as-synthesized samples using different synthesis methods have been measured using N2 adsorption experiments to evaluate the changes in the specific surface areas and pore volumes upon the introduction of [emim][Ac] to the support materials. A significant decrease in the porosity was realized for the [emim][Ac]-confined samples especially when using wet impregnation synthesis method compared to the dry mixing approach. The crystal structures of the MOF-177 and MIL-101 were found to be maintained after the synthetic steps, with some reductions in the X-ray diffraction peak intensities. No improvements in the CO2 uptakes could be achieved for the MIL-101 samples using both synthesis strategies, whereas the [emim][Ac]@MOF-177 samples prepared using wet impregnation method, has shown a remarkable enhancement in the CO2 capacity up to 0.3 mmol/g at 0.15 bar and 303 K. Moreover, the adsorption kinetics in MOF-177 based samples was found to be significantly fast as depicted from the first order rate constant values. The [emim][Ac]@MOF-177 samples exhibited a substantially stable cyclic adsorption–desorption performance up to 10 successive cycles with a considerably fast desorption kinetics.

Pi electron cloud mediated separation of aromatics using supported ionic liquid (SIL) membrane having antibacterial activity

Supported ionic liquid (SIL) membranes using imidazolium based ionic liquids and hydrophobic PTFE base membrane were used for the π electron mediated separation of aromatic compounds including dyes in aqueous and non-aqueous medium. The FTIR of SIL membranes showed the signature of the functionalities for both base membrane and the imidazolium moiety. A significant reduction in contact angle, especially the dynamic contact angle, was observed for SIL membranes compared to the virgin membrane indicating the enhancement in surface hydrophilicity of the membrane, while considerable changes zeta potential was seen at different pH indicating the modification in surface charge. The SEM image confirmed the pore filling of base membrane with ionic liquids. The stability of the SIL membranes were studied using hexane, water and DMF as solvents. Tuning the anionic moieties, ionic liquids were utilized for aqueous and non-aqueous application through SIL membranes. For non-aqueous applications, the trend in separation efficiency was found to be divinylbenzene > styrene > toluene, which was attributed to the more π electron cloud density on extended conjugation leading to favorable interaction with ionic liquid influencing its transfer through SIL membranes. Preferential separation of Congo red (CR) and Ramazol Brilliant Blue R (RBBR) was achieved in water based application of the SIL membranes. The anti-microbial activity of these SIL membranes were investigated using gram-positive bacteria (Staphylococcus aureus and Pseudomonas aeruginosa). More the number of carbon atom on the side chain of the imidazolium ring, more antimicrobial activity was observed.

Oxidative Desulfurization of Diesel Fuel Using a Brønsted Acidic Ionic Liquid Supported on Silica Gel

A novel heterogeneous catalyst was prepared by supporting the ionic liquid (IL) 1-octyl-3-methylimidazolium hydrogen sulfate ([Omim][HSO4]) in the silica-gel matrix using a sol–gel method and employed in oxidative desulfurization of a model oil containing dibenzothiophene (DBT) and real diesel fuel. The properties of the supported ionic liquid (SIL) were characterized by FT-IR, TGA, BET-BJH, SEM-EDS, and PSA. The results showed that the ionic liquid was successfully incorporated in the silica-gel matrix, and a catalyst having high surface area was prepared. The effects of H2O2/DBT molar ratio (O/S), temperature, SIL/oil mass ratio, initial S content, and sulfur species on the sulfur removal of the model oil were studied. The highest DBT removal efficiency of 99.1% was obtained with the prepared catalyst having 17 wt % supported IL loading in the conditions of SIL/oil (w/w) of 1:3 and O/S molar ratio of 5 in 50 min at 50 °C. The prepared catalyst can be efficiently applied in oxidative desulfurization with...

Supported Ionic Liquids: A Versatile and Useful Class of Materials.

Supported ionic liquids (SILs) represent a class of materials with peculiar properties and a huge potential regarding their possible applications in different fields of chemistry. Herein, we report our ongoing research about the use of SILs as support for organocatalysts, their role as catalysts themselves, and their application as support and stabilizers of palladium nanoparticles (PdNPs). The use of SILs based materials allowed achieving good results. Moreover, in some cases, after the functionalization of the catalytic species with an ion-tag moiety, a release and catch approach was employed in order to improve the catalytic activity and to facilitate the recovery of the hybrid system formed by the catalyst adsorbed onto SILs materials. All the reported examples demonstrate the versatility of such SILs materials, which can represent powerful tools able to exert a large number of functions.