Synthesis Of Deep Eutectic Solvents Research Articles

Solvent‐Mediated Synthesis of Functional Powder Materials from Deep Eutectic Solvents for Energy Storage and Conversion: A Review

AbstractDeveloping advanced electrochemical energy storage and conversion (ESC) technologies based on renewable clean energy can alleviate severe global environmental pollution and energy crisis. The efficient preparation of functional electrode materials via a simple, green, and safe synthesis process is the key to the commercial feasibility of these ESC systems. Deep eutectic solvents (DESs) with easy‐tunable solvent properties and recyclable features have emerged as novel solvent systems for designing and synthesizing various functional powder materials for ESC devices. In this paper, the application of DESs in the synthesis of energy‐related functional powder materials is systematically reviewed. After briefly introducing the classification and synthesis of DESs, their critical roles in synthesizing powder materials are discussed. Then, the recent advances of DES‐derived powder materials in ESC, including batteries, fuel cells, supercapacitors, and water splitting, are described in detail from the perspective of preparation‐structure‐activity. Finally, some challenges and development directions of the DESs‐mediated synthesis of powder materials with high electrochemical performance for ESC applications are outlined.

One-step Synthesis of Deep Eutectic Solvents and Dissolution of Kraft Lignin

Abstract: Lignin is a very abundant biopolymer with great potential to produce other high-value polymers with aromatic groups. Its valorization has been limited principally by its poor solubility in conventional organic solvents, which makes it difficult to deconstruct or transform it into other products with higher added value. In this work, we describe a one-pot procedure to prepare vari-ous Deep Eutectic Solvents and study their ability to dissolve Kraft lignin with the aid of micro-wave dielectric heating efficiently. Background:: Lignin is a widely available aromatic biopolymer that is largely discarded or used as a low-value fuel when separated in paper production processes, so researchers are engaged in the development of lignin dissolution processes that allow its easy deconstruction and transfor-mation into other products with higher added value. Objective:: The main objective of this work is to find deep eutectic solvents capable of dissolving significant quantities of lignin with the aid of microwaves as a heating source. Method:: The present work developed a simple, fast, and efficient method to dissolve lignin using Deep Eutectic Solvent/acetonitrile as solvents and irradiation by dielectric microwave heating. Results:: Most of the DESs studied achieved significant dissolution of purchased lignin with com-mon organic solvents by employing microwave irradiation as the heating method. Conclusion:: Some DESs studied in this work are good alternatives as solvents for lignin solvent option of simple preparation from renewable precursors from biomass, such as glycerol, choline chloride, and urea, of low toxicity and cost for this application. The effectiveness of these systems appears to be based on molecular recognition by hydrogen bonding interactions involving the three species that make up the eutectic and the hydroxyl groups of the lignin. These solvents can be recovered and recycled.

Visible‐Light‐Mediated Amide Synthesis in Deep Eutectic Solvents

AbstractIn the present study, for the first time environmentally friendly deep eutectic solvents (DESs) are used as reaction media to perform an efficient, simple and straightforward photocatalytic amide synthesis at room temperature using thioacids and amines. This method features mild conditions, a broad substrate scope, high yields (≤99%) under ambient conditions with air and moisture tolerance. Moreover, the applied operationally mild reaction conditions tolerate the presence of several different functional group substituents on the amine counterpart. Finally, the developed approach allows the recycling of the reaction medium and catalyst for at least three consecutive cycles without a significant decrease in the reaction yield.

Unexpected formation of hexahydroxanthenediones by electrochemical synthesis in deep eutectic solvents

The current study reports the unexpected formation of xanthene-1,8-diones upon attempt to perform Biginelli reaction by reacting cyclohexanedione, thiourea and different aldehydes under electrochemical conditions in either ethanol or deep eutectic solvents and utilizing Amberlyst-15® as a heterogeneous acidic catalyst. The Biginelli reaction product; hexahydroquinazoline-5-one, was not observed even upon using varying amounts of catalysts, different reaction times, different types of electrodes, and different types of substituted benzaldehydes. The mechanism of formation of xanthene-1,8-dione was followed up by cyclic voltammetry.

Synthesis of deep eutectic solvents of N, N, N-trimethyl butylsulphonate ammonium hydrosulfate-urea and their performance investigation as electrolytes in fuel cells

Synthesis of deep eutectic solvents of N, N, N-trimethyl butylsulphonate ammonium hydrosulfate-urea and their performance investigation as electrolytes in fuel cells

Synthesis of deep eutectic solvents based on triethylamine and organic acids and their application in fuel oil denitrogenation: A theoretical and experimental study

In this work, three deep eutectic solvents (DESs) triethylamine/formic acid ([Et3N/FA]), triethylamine/acetic acid ([Et3N/PA]), triethylamine/propionic acid ([Et3N/AA]) were synthesized and were used for extractive denitrogenation of model oil. Among them [Et3N/PA] exhibited reasonably high extraction efficiency for both indole and quinolone. Structure optimization, electrostatic potential analysis and reduced density gradient analysis were performed to explore the synthesis mechanism of DESs and extractive denitrogenation mechanism by DESs taking [Et3N/PA] as a representative. The structure of [Et3N/PA] were characterized by FTIR and NMR. Results indicate that both strong hydrogen bond and van der Waals are the majorforcefor DESs synthesis. Both hydrogen bonds and van der Waals are responsible for indole removal, while only van der Waals is responsible for quinolone removal. The effect of factors on extraction efficiency was also investigated and results indicate that [Et3N]/[PA] has the advantages of short equilibrium time, ability to deal with fuel oils with a wide range of nitrogen contents, excellent performance near room temperature. The presence of olefins and aromatics in fuel oil has negligible negative influence on the extraction efficiency of indole and quinolone. Furthermore, [Et3N/PA] exhibits excellent regeneration performance. Consequently, [Et3N/PA] is a promising extractant for fuel oil denitrogenation.

One-Pot Synthesis of Deep Eutectic Solvents Containing Three-Dimensional Polymeric Materials with Excellent Catalytic Activity in the Knoevenagel Condensation Reaction

Deep eutectic solvents (DESs)-containing three-dimensional (3D) porous organic polymers (termed TAM-BPA-ChCl/Ur, TAM-BPA-ChCl/Gly, and TAM-BPA-Bu4NBr/Im) were obtained via one-pot synthesis by using DESs as green reaction solvents for the first time. The DESs were confined into 3D extended structures during the synthetic process, as revealed by a series of techniques. The DESs-loaded polymeric materials were used to catalyze the Knoevenagel condensation of aldehydes and malononitrile and produced excellent yields at room temperature. As a typical example, the TAM-BPA-ChCl/Ur sample as a heterogeneous catalyst can be recovered easily and shows stable catalytic activity. This research presents a feasible method to prepare functional complex materials involving DESs and porous polymers.

The possibility of using DES based on polypropylene glycol 425 and tetrabuthylammonium bromide in the extraction processes of transition metals

Traditionally, the method of liquid extraction is used to extract metals from aqueous. This work is devoted to the combination of perspective alternative for hazardous solvents (aqueous two-phase systems based on water-soluble polymers) and the novel deep eutectic solvents in the non-ferrous metals extraction processes. In this work, the synthesis of deep eutectic solvent based on a water-soluble polymer (PPG-425) and tetrabutylammonium bromide (TBAB) by stirring for 10 minutes at 80° C has been shown. The obtained results showed not only the possibility of using DES in the metal extraction process, but the selectivity to the Fe(III) and Zn(III), the distribution coefficients were 71.64 and 25.17 respectively. The metal concentrations were determined spectrophotometrically using 4-(2-pyridylazo)resorcinol. This work shows the perspectives of using DESs in the metal extraction processes.

DEEP EUTECTIC SOLVENTS AS AN ADDITIVE IN MODIFICATION OF MEMBRANEFOR NANO- AND ULTRA- FILTRATION: PHYSIC-CHEMISTRY CHARACTERISTICS, FTIR STUDY AND ELECTROCHEMICAL BEHAVIOR

Deep eutectic solvents (DESs) are a new class of solvents that can offset some of the primary drawbacks of typical solvents and ionic liquids. They are synthesized by simply mixing the components that interact with each other through hydrogen bonds, and form a eutectic mixture with a melting point much lower than each component individually. Deep eutectic solvents is usually liquid at temperatures below 100 °C. Thanks to these great advantages, deep eutectic solvents is attracting more and more attention in many areas of research. Very recently, great attention has been paid to new pioneering attempts aiming at deep eutectic solvents into the field of chemical engineering, including membrane science and technology. Even if just a same works have been currently reported in applying deep eutectic solvents in membranes, the consideration on this new type of solvents is continuously growing. New deep eutectic solvents based on choline chloride (ChCl)–lactic acid (1:2 M ratio) was obtained and its electrochemical characteristics was studied. The synthesis of deep eutectic solvents was confirmed by FA nuclear magnetic resonance (NMR) spectrometry method. FTIR study provided further details into hydrogen bonding upon mixing. FTIR results confirmed that H-bonds, occurring between two components in deep eutectic solvents, were the main force leading to the eutectic formation. The frequency at 3221 cm−1 can be attributed to the oscillations of the O-H bond in the formation of OH-Cl-ChCl. The main physicochemical characteristics of deep eutectic solutions (density, pH) are determined. The electrochemical behavior was investigated of choline chloride (ChCl)–lactic acid deep eutectic solvent (DES) by cyclic voltammetry. The method of cyclic voltammetry found that the oxidation of deep eutectic solvents is fixed at a potential of Ea1 = 0.54 V.

One-step synthesis in deep eutectic solvents of Pt3Sn1-SnO2 alloy nanopore on carbon nanotubes for boosting electro-catalytic methanol oxidation

A bimetallic catalyst, Pt3Sn1-SnO2 alloy nanopore (ANNP) supported on multi-walled carbon nanotubes (MWCNTs) was prepared in a new media: deep eutectic solvents (DESs) (referred to Pt3Sn1-SnO2/CNTs-D). TEM and other characterization results show that DESs leads to the formation of pores, which is conducive to catalysis. The Pt3Sn1-SnO2/CNTs-D showed higher catalytic performance toward methanol and better CO anti-poisoning capability (peak current: 316.2 mA mgPt−1, onset potential: 0.38 V, peak potential: 0.55 V) compared with Pt/CNTs-D (synthesised in DESs) (200.1 mA mgPt−1, 0.46 V, 0.59 V), Pt/CNTs-W (synthesized in water) (110.8 mA mgPt−1, 0.65 V, 0.68 V) and commercial Pt/C (75.3 mA mgPt−1, 0.57 V, 0.65 V). This study suggests an appropriate strategy for preparation of Pt-based electrocatalysts with high performance for direct methanol fuel cells (DMFCs) applications.

Dispersive solid phase extraction combined with solidification of floating organic drop–liquid–liquid microextraction using in situ formation of deep eutectic solvent for extraction of phytosterols from edible oil samples

In this study, a dispersive solid phase extraction method was combined with solidification of floating organic drop–liquid–liquid microextraction based on in situ synthesis of deep eutectic solvent. It was used for the extraction of some phytosterols from edible oil samples. The extracted analytes were quantified by gas chromatography–mass spectrometry. In this procedure, the sample lipids are saponified with sodium hydroxide and then the analytes are adsorbed onto an octadecylsilane sorbent. After that the analytes are desorbed from the sorbent with ethanol as an elution solvent and the eluant is diluted with deionized water to obtain a homogenous solution. Then, a few amounts of choline chloride and n-butyric acid are dissolved in the solution and transferred into a water batch adjusted at 75 ⁰C for 5 min. During this period Choline chloride and n-butyric acid form a deep eutectic solvent (extraction solvent) dispersed in whole parts of the solution. The obtained cloudy solution is placed into an ice bath. The extraction solvent is collected and solidified on the top of the solution. Finally, it is removed and allows melted at room temperature and an aliquat of the solution is injected into the separation system. Validation of the method showed that limits of detection and quantification were in the ranges of 0.52–1.6 and 1.7–5.6 ng mL–1, respectively. Enrichment factors and extraction recoveries of the analytes ranged from 312 to 375 and 75–90%, respectively. The method had a proper percision with relative standard deviations less than ≤8.2% for intra– (n = 6) and inter–day (n = 6) precisions at a concentration of 15 ng mL–1 of each analyte. Finally the method was successfully used for determination of the analytes in some edible oil samples.

Limiting factors and optimization of glycolipid synthesis in deep eutectic solvents

Limiting factors and optimization of glycolipid synthesis in deep eutectic solvents

Development and applications of deep eutectic solvent derived functional materials in chromatographic separation.

Deep eutectic solvents have received increasing attention over the past decade, and the green and versatile nature makes them important media for developing environmentally friendly and sustainable technologies. In addition to act as green alternatives to traditional organic solvents, deep eutectic solvents offer tremendous opportunities to produce different kinds of emerging functional materials. The present review highlights the recent development and applications of deep functional materials based on deep eutectic solvents as novel adsorbents for diverse analytes in complex matrices. The type, preparation, and unique properties of deep eutectic solvents, the synthesis of deep eutectic solvent derived materials, as well as their applications in chromatographic separation are described. We aim to demonstrate that deep eutectic solvents not only allow the design of eco-friendly extraction processes but also open straightforward access to advanced materials in sample preparation.

Absorptive Desulfurization of Model Biogas Stream Using Choline Chloride-Based Deep Eutectic Solvents

The paper presents a synthesis of deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor and phenol (Ph), glycol ethylene (EG), and levulinic acid (Lev) as hydrogen bond donors in 1:2 molar ratio. DESs were successfully used as absorption solvents for removal of dimethyl disulfide (DMDS) from model biogas steam. Several parameters affecting the absorption capacity and absorption rate have been optimized including kinds of DES, temperature, the volume of absorbent, model biogas flow rate, and initial concentration of DMDS. Furthermore, reusability and regeneration of DESs by means of adsorption and nitrogen barbotage followed by the mechanism of absorptive desulfurization by means of density functional theory (DFT) as well as FT-IR analysis were investigated. Experimental results indicate that the most promising DES for biogas purification is ChCl:Ph, due to high absorption capacity, relatively long absorption rate, and easy regeneration. The research on the absorption mechanism revealed that van der Waal interaction is the main driving force for DMDS removal from model biogas.

Template-free synthesis of platinum hollow-opened structures in deep-eutectic solvents and their enhanced performance for methanol electrooxidation

As a novel non-aqueous green solvent that can deem to be the optimal substitution of conventional solvents and ionic liquids, deep-eutectic solvents (DESs) have attracted significant attention from academia and industry in terms of chemical synthesis in recent years. Herein, we report the highly effective preparation of Pt nanoparticles with hollow-opened structures (Pt HOSs) as an efficient electrocatalyst for methanol oxidation reaction (MOR) via a facile template-free solvothermal synthesis in DESs. The as-obtained Pt HOSs are consisted of well assembled secondary and tertiary branches, which can remarkably improve the utilization efficiency and electrocatalytic activity of Pt via promoting the access of electroactive species to the full-extent Pt surface. In this regard, the as-prepared Pt HOSs possess higher electrochemically active surface areas (ECSAs) and show improved electrochemical properties for MOR. Furthermore, the Pt HOSs retain a higher reactivity after the long-term testing compared with commercial Pt black, suggesting that they have enhanced electrocatalytic durability. In specific, the rational design of Pt HOSs in DESs may enrich the synthetic strategies for producing more electrocatalysts with impressive activity and stability.

Reshaping Ullmann Amine Synthesis in Deep Eutectic Solvents: A Mild Approach for Cu-Catalyzed C-N Coupling Reactions With No Additional Ligands.

The CuI-catalyzed Ullmann amine cross-coupling between (hetero)aryl halides (Br, I) and aromatic and aliphatic amines has been accomplished in deep eutectic solvents as environmentally benign and recycling reaction media. Under optimized conditions, the reaction proceeds smoothly under mild conditions (60–100°C) in air, in the absence of ligands, with a catalyst (CuI) loading of 10 mol% and K2CO3 (aliphatic primary and secondary amines) or t-BuOK (aromatic amines) as the base. A variety of amines have been synthesized in yields up to 98% with a broad substrate scope.

One-step synthesis in deep eutectic solvents of PtV alloy nanonetworks on carbon nanotubes with enhanced methanol electrooxidation performance

We report a simple one-step chemical reduction strategy in deep eutectic solvents (DESs) for the fabrication of a PtV alloy nanonetwork (ANN)/multiwalled carbon nanotube (MWCNT) nanohybrid, which exhibits excellent electrocatalytic performance in both activity and stability for the methanol oxidation reaction (MOR). The as-synthesized nanohybrid was characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, confirming the formation of a porous nanonetwork structure composed of smaller PtV alloy nanoparticles (~3.8 nm) and the presence of strong electronic transfer interactions between Pt and alloyed V. The electrochemical properties of catalysts for the MOR were evaluated by using cyclic voltammetry and chronoamperometry techniques. The electrocatalytic activity, durability and CO tolerance ability of PtV ANNs/MWCNTs toward the MOR are found to be considerably higher than those of the Pt/MWCNT and commercial Pt/C catalysts. This investigation of the effect of several reaction parameters (e.g., scan rate and methanol concentration) indicates that the electrocatalytic oxidation of methanol on PtV ANNs/MWCNTs is a diffusion-controlled electrochemical process. The performance enhancement mechanism of MOR on the PtV ANN/MWCNT catalyst is analyzed based on the structure and electrochemical studies.

In situ deep eutectic solvent pretreatment to improve lignin removal from garden wastes and enhance production of bio-methane and microbial lipids

Biomass pretreatment can improve the conversion efficiency of bioenergy production. Liquid hot water (LHW) pretreatment is a truly green pretreatment due to its zero chemical use, but has the disadvantages of low lignin removal and pseudo-lignin formation. A modified liquid hot water (MLHW) process based on in situ synthesis of deep eutectic solvent (DES) could efficiently improve delignification of Roystonea regia leaves (LR) and leaf sheaths (LSR). LSR was less recalcitrant than LR, and its characteristics of higher porosity (34.8%) and thinner cell walls (5.2 μm) for LSR contributed it higher lignin removal (53.6%) and lower choline chloride (ChCl) consumption (H2O-ChCl mass ratio of 2:1) than those (44.6% and 1:2) from LR. Moreover, a great improvement of 309.0% in bio-methane yield was achieved for the MLHW-treated LSR. In addition, in situ DES in MLHW had good biocompatibility with cellulase, microalgae, and yeast.

Concave cubic PtLa alloy nanocrystals with high-index facets: Controllable synthesis in deep eutectic solvents and their superior electrocatalytic properties for ethanol oxidation

Due to their strong electronic interactions and excellent electrochemical properties, noble metal-based rare earth nanoalloys are considered to be promising electrocatalytic materials for fuel cell applications. However, due to the limitation of the very negative reduction potential for rare earth metals, the wet chemical or electrochemical preparation of noble metal/rare earth nanoalloys is still challenging. Herein, we report a novel and effective strategy for the electrochemical synthesis in deep eutectic solvents of concave cubic PtLa alloy nanocrystals with high-index facets and superior electrocatalytic properties for the ethanol oxidation reaction. Scanning electron microscopy and transmission electron microscopy characterizations confirm that the concave cubic PtLa alloy nanocrystals of approximately 47.5 nm in size are uniformly electro-deposited on the glassy carbon substrate in deep eutectic solvents and are bounded with the {410} and adjacent high-index facets. X-ray photoelectron spectroscopy analysis indicates the presence of strong charge transfer interactions from La to Pt atoms in the concave cubic PtLa alloy nanocrystals. Due to the synergetic effect of the high-index facets and the charge transfer interactions between Pt and La, the synthesized concave cubic PtLa alloy nanocrystals exhibit enhanced specific current activity and long-term durability for the ethanol oxidation reaction.

Physicochemical properties of Bi-containing ionic liquid analogs based on choline chloride

The preparation and characterization of homogeneous and colorless ionic liquid analogs(ILAs) containing choline chloride(ChCl), malonic acid and bismuth chloride were investigated. The structure of the above mixture was preliminarily analyzed, and then the physicochemical properties including viscosity, conductivity and density were investigated as functions of temperature and composition. Additionally, the thermal stability of the ILAs and the electrochemical behavior of Bi3+ ions in the medium were studied. Structure analysis reveals that the synthesis of deep eutectic solvents(DESs) is closely related to the formation of hydrogen bonds between malonic acid and ChCl, with their viscosity, conductivity and density being greatly dependent on the temperature and composition. Thermogravimetric analysis demonstrates that the ILAs are very stable between room temperature and 398.15 K. And the electrochemical experiments indicate that the bismuth films can be successfully deposited from this ILAs and the deposition mechanism of bismuth is a rather irreversible process. The surface morphology of bismuth films deposited on Cu substrates was very compact and smooth. Thus, ChCl-malonic acid DESs were shown to be a good alternative to aqueous solvents for various deposition-related applications.