Amino-functionalized Ionic Liquid Research Articles

Functionalized Ionic Liquids-Modified Metal-Organic Framework Material Boosted the Enzymatic Performance of Lipase.

The development of immobilized enzymes with high activity and stability is critical. Metal-organic frameworks (MOFs) have attracted much academic and industrial interest in the field of enzyme immobilization due to their unique properties. In this study, the amino-functionalized ionic liquid (NIL)-modified metal-organic framework (UiO-66-NH2) was prepared to immobilize Candida rugosa lipase (CRL), using dialdehyde starch (DAS) as the cross-linker. The results of the Fourier transform infrared (FT-IR) spectra, X-ray powder diffraction (XRD), and scanning electronic microscopy (SEM) confirmed that the NIL was successfully grafted to UiO-66-NH2. The CRL immobilized on NIL-modified UiO-66-NH2 (UiO-66-NH2-NIL-DAS@CRL) exhibited satisfactory activity recovery (79.33%), stability, reusability, and excellent organic solvent tolerance. The research results indicated that ionic liquid-modified UiO-66-NH2 had practical potential for application in enzyme immobilization.

A novel ionic liquid absorbent with polyamidoamine dendrimer as cations for efficient CO2 absorption

To achieve excellent absorptive loading and low viscosity, a novel amino-functionalized ionic liquid [G1.0 PAMAM] [2-MI] combined with water for CO2 capture is proposed in this work. The concentration of [G1.0 PAMAM] [2-MI], absorption temperature, and aeration rate were optimized by using Response Surface Methodology based on Box-Behnken design, and the model predictions were in good agreement with the experimental data. The results illustrated that the absorption loading of 42.71 wt% [G1.0 PAMAM] [2-MI]/H2O was 6.81 mol CO2/mol ILs (38.5°C, 100 mL/min), which was much higher than that of MEA /H2O, and the regeneration efficiency was maintained at 89.5 % after the eighth regeneration cycle. With the combined effect of 2-MI and water, the viscosities of the solution before and after absorption at 40°C were 35.3 and 53.8 mPa·s, respectively, which were significantly lower than those of the majority of ionic liquid absorbents. The reaction mechanism of [G1.0 PAMAM] [2-MI] with CO2 was demonstrated by 13C NMR to be a synergistic combination of a zwitterionic mechanism and a base-catalyzed hydration mechanism to produce carbamate and carbonate/bicarbonate (CO32–/HCO3–).

Inductive effect in amino functionalized ionic liquids modified TS-1 nanosheets for efficiently sunlight-driven CO2 reduction

Photocatalytic technology for converting CO2 into useful chemicals or clean energy is an effective strategy to solve today's energy and environmental problems. In this study, we present a direct photocatalytic pathway for the conversion of CO2-to-CO involving the formation and activation of carboxyl intermediates over amino-functionalized ionic liquid (3-aminopiperidine hydrochloride, [3APip]Cl)-modified titanium silicalite-1 (TS-1) molecular sieve nanosheets. Various in-situ characterizations reveal that the key to activating this pathway lies in the CO2 adsorption capacity and the efficiency of photoexcited charge migration induced by [3APip]Cl in the hybrid catalyst. In the above catalytic pathway, CO2 molecules are first adsorbed on the surface of the [3APip]Cl/TS-1 hybrid catalyst under the induction of amino groups in the ionic liquid. Then, these adsorbed CO2 are activated and transformed into carboxyl intermediate, which can be further converted into CO and CH4 through photoexcited electrons captured by [3APip]Cl. Based on the results of CO2 reduction performance, the optimized [3APip]Cl/TS-1 hybrid catalyst achieves a 6-fold increase, and the CO selectivity is 83.0%. This research provides new insights into the CO2 reduction pathway in mild conditions and emphasizes the importance of the adsorption–activation tandem process for enhancing photoactivity and selectivity.

Kinetics of novel non-corrosive amino functionalized ionic liquid organic solution for CO2 capture

Extensive energy consumption is a challenge for developing industrial carbon capture absorbents. A novel amino functionalized ionic liquid (AFIL) organic solution, tetraethylene pentamine 5-amino-4-imidazolecarboxamide/n-propanol/ethylene glycol ([TEPAH][AICA]/NPA/EG), is considered as a promising absorbent due to its high CO2 absorption capacity and low energy consumption. However, its industry application potential still needs to be further evaluated for carbon capture process. In this work, thermodynamics, kinetics and corrosive behavior of [TEPAH][AICA]/NPA/EG solution were investigated. The regeneration energy consumption was 2.30 GJ⋅t−1 CO2, which was 39.5% lower than the benchmark monoethanolamine (MEA) solution. The mass transfer reaction kinetic model was established, showing that the reaction between CO2 and [TEPAH][AICA]/NPA/EG solution followed fast pseudo-first-order. The enhancement factor and reaction rate constant increased with the increase of absorption temperature, while they showed a decreasing trend with the increase of absorption loading. The relationship between the second-order rate constant and temperature was expressed as k2=7.2075×108exp-3093.5T. The activation energy was 25.72 kJ·mol−1. During absorption process, the dominant mass transfer resistance gradually changed from gas phase to liquid phase. In addition, the absorbent presented non-corrosive behavior after saturated absorption, which was superior than the MEA absorbent for storage and transportation in the carbon capture technology. To be concluded, the above results showed that the [TEPAH][AICA]/NPA/EG solution owned great potential for future industrial application.

Thermodynamic Properties and Intermolecular Interacting Behaviors of Amino-Functionalized Ionic Liquid Binary Mixtures of 1-Aminopropyl-3-methylimidazolium Tetrafluoroborate with Dimethyl Sulfoxide and Acetonitrile

Thermodynamic Properties and Intermolecular Interacting Behaviors of Amino-Functionalized Ionic Liquid Binary Mixtures of 1-Aminopropyl-3-methylimidazolium Tetrafluoroborate with Dimethyl Sulfoxide and Acetonitrile

Application of ionic liquids in CO2 capture and electrochemical reduction: A review

As a new type of green solvent with non-volatility, high thermal stability, high conductivity and various adjustable properties, ionic liquid (IL) has been widely used in the capture and electrochemical reduction of carbon dioxide (CO2). To date, many studies have been made to investigate CO2 capture by using different types of ILs and CO2 electrochemical reduction (CO2ER) with ILs as either electrolyte or other catalytic active components. Some structure–activity relationships between the structure and adsorption or catalytic properties of ILs have been found. Herein, the absorption performances and mechanisms of conventional ILs, amino-functionalized ILs, non-amino functionalized ILs and supported ILs for CO2 capture, as well as the performances and action mechanisms of ILs as the electrolyte, electrolyte additive, and/or electrode modifier in the process of CO2ER are summarized. Many researches indicate that the unique interaction between the anion or cation of IL and CO2 has a significant contribution to promote the absorption and conversion of CO2. However, the ILs used for CO2 capture and electrochemical reduction should be further explored. Especially, a more in-depth investigation of the adsorption and catalytic mechanisms with the help of quantum chemical calculation, molecular simulation, and in situ characterization techniques is necessary. It is expected to design and develop more efficient ILs used for CO2 capture and conversion on a large scale.

Surface Modification of Magnetic ZIF-90 Nanoparticles Improves the Microenvironment of Immobilized Lipase and Its Application in Esterification.

Interactions of enzymes with supports significantly affect the activity and stability of immobilized enzymes. Herein, amino-functionalized ionic liquid (IL)-grafted magnetic zeolitic imidazolate framework-90 (MZIF-90) was prepared and used to immobilize porcine pancreatic lipase (PPL). The nanocomposites were fully characterized; meanwhile, the interactions between ILs and ZIF-90 were calculated based on density functional theory. The prepared biocatalyst (PPL-ILs/MZIF-90) had a lipase loading of 178.3 mg/g and hydrolysis activity up to 287.5 U/g. When the biocatalyst was used to synthesize isoamyl acetate, the reaction media, molar ratio of alcohol/acid, temperature, and reaction time were optimized. Under the optimized reaction conditions (in hexane, alcohol/acid = 3:1, under 45 °C, reacted for 9 h), the ester yield reached 85.5%. The results of the stability test showed that PPL-ILs/MZIF-90 retained 88.7% of the initial activity after storing for 35 days and 92.5% of the initial activity after reusing for seven cycles for synthesizing isoamyl acetate. Moreover, the secondary structure analysis showed that the synthesized supports protected the active conformation of immobilized lipase, which lead to the enhanced catalytic performance. Additionally, the biocatalyst can be easily separated with a magnet, which facilitated the reusability. This study provides insights regarding the application of metal organic framework composites in the field of enzyme catalysis.

Thermodynamic analysis of H2O − 3-aminopropyl tributyl phosphonium glycinate as a working pair for absorption refrigeration system

In this paper, A hydrophilic dual amino-functionalized ionic liquid 3-aminopropyl tributyl phosphonium glycinate ([aP4443][Gly]) with high thermal stability was used as absorbent and the refrigerant was water for the absorption refrigeration system (ARS). The heat capacities of the system were estimated by the differential scanning calorimetry (DSC) with various water mass fractions (w1) (0.004 to 0.6993) and temperatures (285 K to 365 K), and a polynomial equation on temperature and mass fraction of ionic liquid (w2) was associated. Between the experimental and estimated values, the average relative deviation (ARD) was 0.66%. The vapor–liquid equilibrium (VLE) data of the H2O–[aP4443][Gly] binary mixture was correlated using the electrolyte nonrandom two-liquid (eNRTL) model, and the binary mixture's excess thermodynamic properties were simulated. The first and second laws of thermodynamics were used to simulate the performance of a single-effect ARS with a solution heat exchanger (SHE). The ARS simulation results show that the coefficient of performance (COP) of the system with H2O–[aP4443][Gly] as the working pair is higher than that of the conventional working pair NH3-H2O but slightly lower than that of H2O-LiBr. Furthermore, the effect of generator temperature (Tg) on ARS is investigated; simulation results show that the ARS of the novel working pair has a higher COP value at higher generator temperature, indicating that H2O–[aP4443][Gly] has the potential to be a new type of absorption refrigeration working pair.

Thermodynamics and kinetics of novel amino functionalized ionic liquid organic solvent for CO2 capture

The main disadvantage of commercial absorption solution for CO2 capture from flue gas is extensive energy consumption. A novel amino-functionalized ionic liquid (AFIL) organic solution of tetraethylene pentamine 2-methylimidazolium/N-propanol/ethylene glycol ([TEPAH][2-MI]/NPA/EG) is considered as a promising candidate absorption system because of its efficient CO2 capture performance and low energy consumption. The thermodynamics and kinetics studies are very essential for evaluating the absorbent and its potential of future practical industrial application. In this work, the performance in these two aspects of [TEPAH][2-MI]/NPA/EG solution were investigated. The regeneration energy consumption was 2.98 GJ·t−1 CO2, which was 21.6% lower than that of benchmark monoethanolamine (MEA) aqueous solution, and the energy saving advantage was embodied in sensible heat and latent heat. Kinetic analysis showed that chemical reaction of CO2 absorption into [TEPAH][2-MI]/NPA/EG solution took place in the pseudo-first-order reaction. The reaction rate constant and enhancement factor increased with the increase of absorption temperature, while those showed a decreasing trend with the increase of absorption loading. The relation between the second-order rate constant and temperature was expressed as k2=5.6192×108exp-3111.6T, and the activation energy was further calculated as 25.87 kJ·mol−1. Compared with those of MEA and several traditional ionic liquid solutions, these parameters indicated a stronger reaction ability of the novel system. Moreover, the mass transfer resistance of gas and liquid phase changed constantly during the absorption process, and the dominant role of mass transfer resistance gradually changed from the gas phase to liquid phase. The thermodynamics and kinetics of CO2 capture revealed that the [TEPAH][2-MI]/NPA/EG solution had an excellent application potential in the future.

Sustainable ionic liquid organic solution with efficient recyclability and low regeneration energy consumption for CO2 capture

• A novel AFIL organic solution was proposed for CO 2 capture. • The novel AFIL organic solution has obvious advantage in the recyclability and viscosity. • The regeneration energy was 2.30 GJ·t −1 CO 2 and 39.5% lower than that of MEA/water. • The reaction mechanism of [TEPAH][AICA]/NPA/EG solution was comprehensively elucidated. A novel sustainable amino functionalized ionic liquid (AFIL) organic solution of tetraethylene pentamine 5-amino-4-imidazolecarboxamide/n-propanol/ethylene glycol ([TEPAH][AICA]/NPA/EG) was proposed for CO 2 capture to reduce the regeneration energy consumption. The solution had an efficient absorption loading of 1.78 mol·mol −1 , and it still maintained a good recyclability after 10 cycles (regeneration efficiency > 88%). Under this condition, the regeneration energy consumption was 2.30 GJ·t −1 CO 2 , which was 39.5% lower than that of MEA/water. The absorption and desorption mechanisms were investigated by 13 C NMR. For CO 2 absorption reaction, N atom of [AICA] − combined with CO 2 to form the carbamate directly, while other amino groups followed the zwitterion formation and deprotonation. Then some carbamates combined with alcohol to form the alkyl carbonates. For CO 2 desorption reaction, both the alkyl carbonates and carbamates combined with AFILH + to decompose, but the alkyl carbonates decomposed completely and a small amount of carbamates remained, indicating that carbonate was easier to decompose than carbamate. The novel [TEPAH][AICA]/NPA/EG solution with low energy consumption and good recyclability, which provides a sustainable strategy for advancing carbon capture technologies.

Hydrodynamics and gas-liquid mass transfer of CO2 absorption into [NH2e-mim][BF4]-MEA mixture in a monolith channel

This is the first work to investigate the hydrodynamics and gas-liquid mass transfer of carbon dioxide (CO2) absorbed into the amino-functionalized ionic liquid (IL) [NH2e-mim][BF4] and monoethanol-amine (MEA) mixture through a vertical circular monolith channel by means of computational fluid dynamics (CFD). It is shown that there are five flow patterns (i.e., bubbly flow, Taylor flow, slug-bubbly flow, slug-annular flow, and annular flow), and Taylor flow is the main flow pattern. The intrinsic kinetics of CO2 absorbed into the [NH2e-mim][BF4]-MEA mixture was obtained, the reaction orders relative to CO2, [NH2e-mim][BF4], and MEA being 1, and the activation energy Ea (19,313 and 28,991 J•mol−1) and pre-exponential factor k0 (3.34×105 and 7.04×106 mol-1•L•min−1) for CO2 absorbed in [NH2e-mim][BF4] and MEA were derived. After the kinetic parameters were imported into the mass transfer model, it was found that the liquid phase volumetric mass transfer coefficient (kLa) in the presence of a chemical reaction can be improved by three to eight times, indicating that mass transfer can be enhanced remarkably by chemical reaction. Moreover, a correlation formula is developed to predict kLa, which agrees well with the simulation results. This work provides a new way to capture CO2 with the combination of IL and MEA in a monolith reactor.

Hollow MOF capsule encapsulated amino-functionalized ionic liquid for excellent CO2 catalytic conversion

• Ionic liquids promote the CO 2 cycloaddition reaction. • The core-shell structure can effectively avoid the leaching of active ILs. • Catalyst shows an excellent catalytic performance under solvent and co-catalyst free conditions. The engineering of highly efficient and stable heterogeneous catalysts for catalytic conversion of CO 2 to high value-added products is highly desirable but presents a great challenge. Herein, we reported the synthesis of a series of multifunctional IL@H-Zn/Co-ZIF composite catalysts with a unique porous hollow capsule structure and encapsulated amino-functionalized ionic liquids (ILs). The unique hollow capsule structure of IL@H-Zn/Co-ZIF provides sufficient space for loading active ILs ([C 2 NH 2 Mim + ][Br − ]) and fast mass transfer of substrate molecules during catalysis. Furthermore, the microporous Zn-ZIF shell can effectively avoid the leaching of active ILs. Benefiting from the unique hollow structure, the resultant IL@H-Zn/Co-ZIF demonstrated excellent catalytic performance (>95% yield), and good recyclability (still remained about 90% activities after 5 cycles) when applied in the CO 2 cycloaddition reaction under solvent and co-catalyst free conditions.

Co-immobilization of laccase and ABTS onto amino-functionalized ionic liquid-modified magnetic chitosan nanoparticles for pollutants removal

This work aims to achieve the co-immobilization of laccase and 2,2-binamine-di-3-ethylbenzothiazolin-6-sulfonic acid (ABTS) to improve removal capability of the biocatalyst for pollutants while avoiding potential pollution caused by ABTS. The laccase was immobilized on magnetic chitosan nanoparticles modified with amino-functionalized ionic liquid containing ABTS (MACS-NIL) based on Cu ion chelation (MACS-NIL-Cu-lac). The carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, x-ray diffraction and etc., and electron paramagnetic resonance confirmed the mediator molecule ABTS on the carrier could also play the role of electron transmission. MACS-NIL-Cu-lac presented relatively high immobilization capacity, enhanced activity (1.7-fold that of free laccase), improved pH and temperature adaptability, and increased thermal and storage stability. The removal performance assay found that MACS-NIL-Cu-lac had a good removal efficiency with 100.0 % for 2,4-dichlorophenol in water at 25 °C, even when the concentration reached 50 mg/L. Reusability study showed that after six catalytic runs, the removal efficiency of 2,4-dichlorophenol by MACS-NIL-Cu-lac could still reach 93.2 %. Additionally, MACS-NIL-Cu-lac exhibited higher catalytic efficiencies with 100.0 %, 70.5 % and 93.3 % for bisphenol A, indole, and anthracene, respectively. The high catalytic performance in pure water system obtained by the novel biocatalyst co-immobilizing laccase and electron mediator ABTS showed greater practical application value.

Novel biphasic amino-functionalized ionic liquid solvent for CO2 capture: kinetics and regeneration heat duty.

Amino-functionalized ionic liquid biphasic solvents present excellent absorption capacity, regeneration ability, and energy consumption savings, which make them a possible candidate for CO2 capture. The kinetics and regeneration heat duty of the [TETAH][Lys]-ethanol-water system capturing CO2 were investigated in this work. The mass transfer and kinetic parameters, including the overall reaction rate constant (kov), the reaction rate constant (k2), and the enhancement factor (E), were assessed at diverse concentrations and temperatures. At 303.15K, the k2 of CO2 capture into the [TETAH][Lys]-ethanol-water solution was 58,907.30m3kmol-1s-1. The Arrhenius equation was introduced to evaluate the relations between k2 and the reaction temperature, which can be presented as [Formula: see text] The regeneration heat duty of the novel biphasic solvent was 35.5 and 62.39% lower than those of [TETAH][Lys]-water and the benchmark monoethanolamine solution, respectively. An efficient absorption performance and lower energy requirement indicate the great potential for this application.

Novel Amino-Functionalized Ionic Liquid/Organic Solvent with Low Viscosity for CO2 Capture.

To achieve low regeneration energy consumption and viscosity, a novel amino-functionalized ionic liquid [TEPAH][2-MI] combined with organic solvents has been proposed for CO2 capture in this work. The results demonstrated that the absorption loading of [TEPAH][2-MI]/N-propanol (NPA)/ethylene glycol (EG) was 1.72 mol·mol-1 (28 wt %, 257 g·L-1), which was much higher than that of monoethanolamine/water, and the regeneration efficiency was maintained at 90.7% after the fifth regeneration cycle. The viscosities of the solution were only 3.66 and 7.65 mPa·s before and after absorption, respectively, which were significantly lower than those of traditional nonaqueous absorbents. The reaction mechanism investigated via 13C NMR and quantum calculations summarized that CO2 first reacted with the amino group of [TEPAH]+ to form the carbamates through the zwitterion formation and protonation process, while CO2 reacted with the N atom of [2-MI]- to directly form the carbamate. Then, some of them further reacted with NPA and EG to form the carbonates. Moreover, Nπ and Nτ tautomers of [TEPAH][2-MI] could convert into each other continuously when CO2 was absorbed. During CO2 desorption, the carbamates and carbonates reacted with AFILH+ to decompose and released CO2 directly.

Laccase immobilized on magnetic nanoparticles modified by amino-functionalized ionic liquid via dialdehyde starch for phenolic compounds biodegradation

Abstract In this work, an efficient biocatalyst immobilized on magnetic nanoparticles modified by amino-functionalized ionic liquid using dialdehyde starch as cross-linker (Fe3O4-NIL-DAS) was fabricated. It was found that activity retention (73.7%), immobilization efficiency (85.8%) and storage stability (>80% of initial activity retained after 30 days) of laccase immobilized on Fe3O4-NIL-DAS (Fe3O4-NIL-DAS@lac) were improved significantly. Moreover, the immobilized laccase could effectively remove phenolic compounds (phenol, 4-chlorophenol and 2,4-dichlorophenol) in a wider temperature and pH range, exhibiting maximum removal efficiencies with 86.1%, 93.6% and 100% for phenol, 4-chlorophenol and 2,4-dichlorophenol, respectively, and high stability was confirmed by retention of 83.5% of the initial activity after six cycles. Fe3O4-NIL-DAS and Fe3O4-NIL-DAS@lac were characterized by transmission electron microscopy, energy dispersive spectrometer, zeta potential analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, magnetic hysteresis loops, circular dichroism and etc. Research results indicated that a novel and efficient strategy for enzyme immobilization to biodegrade phenolic compounds was developed.

Doping amino-functionalized ionic liquid in perovskite crystal for enhancing performances of hole-conductor free solar cells with carbon electrode

Amino group functionalized hydrophobic ionic liquid, 1-ethylamine hydrobromide-3-methylimidazolium hexafluorophosphate (ILPF6) ionic liquid, was employed as the functional monomer to fabricate a carbon-based hole-conductor-free perovskite solar cells with high performances. The photoactive perovskite layer was facilely acquired by one-step spin-coating the precursor solution on a TiO2/FTO electrode surface, and subsequently annealed at an initial annealing at 60 °C for 3 min followed by annealing at 100 °C for 10 min to crystallize. The perovskite precursor solution was prepared by mixing ILPF6 ionic liquid and methylammonium iodide with an equal molar ratio of PbI2. In the optimized conditions, the power conversion efficiency (PCE) was enhanced from 10.08% to 13.01% by doping ILPF6 into the perovskite crystal film. This study demonstrates the multifaceted functions of ILPF6 ionic liquid in improving the efficiency and stability of PSCs. First, ILPF6 can react with PbI2 to form perovskite and can also play a role of the controlling and crosslinking reagent to obtain large grain size and minimize defects. Secondly, ILPF6 can improve the loading amount of perovskite crystals on the TiO2 film. Third, ILPF6 can promote the transport rate of the photogenerated carriers in the perovskite crystal layer. Lastly, ILPF6 ionic liquid with its high hydrophobicity creates a moisture barrier to improve the stability of PSCs effectively. The PSCs were stored under dark in a low relative humidity atmosphere (RH of 20%) at 25 °C without sealing. After 840 h, the PSC can maintain 94% of its initial PCE under the identical intensity illumination. This study demonstrates an excellent strategy to break through the bottleneck of the traditional PSCs and the enhanced effect of ionic liquid for carbon-based PSCs.

A novel biphasic solvent of amino-functionalized ionic liquid for CO2 capture: High efficiency and regenerability

Due to its great potential of energy consumption saving, the biphasic solvent has attracted more and more attention. In the present work, an efficient absorbent of amino-functionalized ionic liquids (AFILs) was dissolved in ethanol-water solvent to form a novel biphasic solvent for CO2 capture. When the concentration of triethylenetetramine l-lysine ([TETAH][Lys]) was 0.5 mol/L and the volume ratio of ethanol-water solvent was 4:6, the [TETAH][Lys] solution separated into two phases after CO2 absorption. Under the optimal conditions, the volume of the CO2-rich phase was about one third of the total volume of the mixture, which meant that only one third of the solution needed to be regenerated and the energy consumption could be greatly reduced. Meanwhile, the loading of the CO2-rich phase contributed about 93% of the total loading of the solution, and its viscosity was only 27.95 mPa s. The regeneration efficiency of the solvent after the 5th absorption-desorption cycle still kept at 91.3%. Based on the experimental and 13C NMR analysis results, the reaction and phase change mechanisms of CO2 capture into the [TETAH][Lys]-ethanol-water solution were clarified. CO2 absorption into [TETAH][Lys] firstly formed carbamate, which would further hydrolyze to HCO3−/CO32− and react with ethanol to form the ethyl carbonate. Due to the limited solubility of these absorption products in ethanol, as well as the good solubility in H2O, the products transferred to the lower phase while the ethanol stayed in the upper phase in the biphasic system.

Choline taurinate: a new biocompatible amino-functionalized ionic liquid as basic catalyst and extraction solvent

Abstract A new biocompatible amino-functionalized ionic liquid composed solely of biomaterials was synthesized from taurine and choline hydroxide, and its physical properties (density, viscosity, miscibility and thermal stability) were also determined. The classic base-promoted three-component cyclic condensation of aromatic aldehydes, malononitrile and dimedone was chosen as the test reaction to demonstrate the catalytic activity of choline taurinate ([Ch][Tau]). The catalyst could be recovered and reused several times with no significant loss of activity. As a basic ionic liquid, [Ch][Tau] can extract acidic compounds from immiscible solvents through acid-base interaction. The extraction process of fluorescent dye Rhodamine B was monitored using ultraviolet-visible (UV-Vis) spectroscopy, by which the percentage extraction rate was determined as 95%.

Immobilization of catalytically active polyoxotungstate into ionic liquid-modified MIL-100(Fe): A recyclable catalyst for selective oxidation of benzyl alcohol

A new polyoxometalate-based catalyst, PW4/DAIL/MIL-100(Fe), was prepared by the immobilization of peroxopolyoxotungstate (PW4O243−, PW4) into the nanocages of dual amino-functionalized ionic liquid (DAIL)- modified MIL-100(Fe) framework. The catalytic behavior of the resulting material was evaluated in the oxidation of benzyl alcohol using TBHP as the oxidant. Moreover, the catalytic performance of PW4/DAIL/MIL-100(Fe) was compared with that of the DAIL free catalyst (HPW4/MIL-100(Fe)). In comparison with the HPW4/MIL-100(Fe) material, the PW4/DAIL/MIL-100(Fe) showed an enhanced catalytic performance in the selective oxidation of benzyl alcohol due to the ability of DAIL groups to form hydrogen bonds and enhancing the accessibility of TBHP.