Bifunctional Ionic Liquid Research Articles

A Comprehensive Comparison Analysis between Ammonium-Based and Phosphonium-Based Bifunctional Ionic Liquids for Metal Extraction and Separation Processes.

A phosphonium-based bifunctional ionic liquid (IL) Cyp-IL was synthesized to recover molybdenum and vanadium from industrial waste resources, such as the spent hydrodesulfurization catalysts. In comparison with the reported versatile Aliquat 336-based ionic liquid, the developed ionic liquid Cyp-IL was investigated for its potential application recovery of vanadium and molybdenum from industrial wastes. To assess the efficiency of the comparative extraction process, a comprehensive comparison analysis was conducted between the ammonium-based bifunctional ionic liquid Aliquat 336 and the developed phosphonium-based bifunctional ionic liquid Cyp-IL. Vanadium and molybdenum in the ionic liquid-loaded phases were selectively precipitated using NH4Cl and BaCl2 solutions in a basic medium. Compared to Aliquat 336-based Ali-IL, Cyp-IL exhibited superior performance in the extraction and separation processes of molybdenum and vanadium such as a recovery rate of Mo 91% and V 82.5% vs Mo 85% and V 72% by the ammonium-based bifunctional ionic liquid Ali-IL. The recovered components, such as molybdenum and vanadium, were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). This method capacitates the sustainable recovery of pure vanadium and molybdenum compounds while minimizing the environmental impact.

Synergic Effects of Ordered Mesoporous Bifunctional Ionic Liquid: A Recyclable Catalyst to Access Chemoselective N-Protected Indoline-2,3-dione Analogous

SBA-15 and organic ionic liquid were incorporated in a post-grafting technique for generating a bifunctional ionic liquid embedded mesoporous SBA-15. The prepared heterogeneous catalyst was employed for the first time to synthesize N-alkylated indoline-2,3-dione at mild conditions to afford excellent yields in a short reaction time. The synthesized DABCOIL@SBA-15 catalyst was meticulously characterized by various techniques, such as FT-IR, solid-state 13C NMR, solid-state 29Si NMR, small-angle X-ray diffraction (XRD), and N2 adsorption–desorption. Further, the morphological behavior of the catalyst was studied by SEM and TEM. The thermal stability and number of active sites were determined by thermogravimetric analysis (TGA). The Hammett equation was used to analyze the synergetic effect of the catalyst and substituent effects on the N-alkylated products of 5-substituted isatin derivatives, which resulted in a negative slope. This negative slope indicates a positive charge in the transition state. Notably, the DABCOIL@SBA-15 catalyst demonstrated its practicality by being reused for seven cycles with consistently high catalytic activity.

New Insights on Y, La, Nd, and Sm Extraction with Bifunctional Ionic Liquid Cyphos IL 104 Incorporated in a Polymer Inclusion Membrane.

In this study, an ionic liquid-based polymer inclusion membrane (IL-PIM) made of (50% polymer-50% CyphosIL104) was used to extract and separate the rare earth elements (REEs) Y, La, Nd, and Sm in chloride solutions. The effect of extraction time and pH was studied to optimize the extraction and separation conditions. The four REEs were effectively extracted at pH 4-5 from both single and mixed metals solutions. However, at pH 2, only Y was extracted. The recovery of the extracted REEs from the loaded PIM was achieved using HNO3 and H2SO4. In the case of La, it was quantitatively back-extracted with H2SO4 after a contact time of 1 h, while up to 4 h was necessary to recover 70% of the extracted Y, Sm, and Nd. Extraction isotherms were studied, and the Freundlich isotherm model was the most adequate to describe the interaction between the PIM and the REEs. Finally, the developed PIM was investigated for the extraction of REEs from mixtures containing other metals, which showed great selectivity for the REEs.

Recovery of Metals from the "Black Mass" of Waste Portable Li-Ion Batteries with Choline Chloride-Based Deep Eutectic Solvents and Bi-Functional Ionic Liquids by Solvent Extraction.

Lithium-ion portable batteries (LiPBs) contain valuable elements such as cobalt (Co), nickel (Ni), copper (Cu), lithium (Li) and manganese (Mn), which can be recovered through solid-liquid extraction using choline chloride-based Deep Eutectic Solvents (DESs) and bi-functional ionic liquids (ILs). This study was carried out to investigate the extraction of metals from solid powder, black mass (BM), obtained from LiPBs, with various solvents used: six choline chloride-based DESs in combination with organic acids: lactic acid (1:2, DES 1), malonic acid (1:1, DES 2), succinic acid (1:1, DES 3), glutaric acid (1:1, DES 4) and citric acid (1:1, DES 5 and 2:1, DES 6). Various additives, such as didecyldimethylammonium chloride (DDACl) surfactant, hydrogen peroxide (H2O2), trichloroisocyanuric acid (TCCA), sodium dichloroisocyanurate (NaDCC), pentapotassium bis(peroxymonosulphate) bis(sulphate) (PHM), (glycine + H2O2) or (glutaric acid + H2O2) were used. The best efficiency of metal extraction was obtained with the mixture of {DES 2 + 15 g of glycine + H2O2} in two-stage extraction at pH = 3, T = 333 K, 2 h. In order to obtain better extraction efficiency towards Co, Ni, Li and Mn (100%) and for Cu (75%), the addition of glycine was used. The obtained extraction results using choline chloride-based DESs were compared with those obtained with three bi-functional ILs: didecyldimethylammonium bis(2,4,4-trimethylpentyl) phosphinate, [N10,10,1,1][Cyanex272], didecyldimethylammonium bis(2-ethylhexyl) phosphate, [N10,10,1,1][D2EHPA], and trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate, [P6,6,6,14][Cyanex272]/toluene. The results of the extraction of all metal ions with these bi-functional ILs were only at the level of 35-50 wt%. The content of metal ions in aqueous and stripped organic solutions was determined by ICP-OES. In this work, we propose an alternative and highly efficient concept for the extraction of valuable metals from BM of LiPBs using DESs and ILs at low temperatures instead of acid leaching at high temperatures.

Extending the application of bifunctional ionic liquid-based integrated capture and conversion of CO2 to produce cyclic carbonates

Nowadays there is an urgent need for mitigating CO2 emissions through clean energy and the development of new carbon capture and utilization (CCU) technologies. Among others, the use of bifunctional ionic liquids (ILs) addressed simultaneously CO2 capture and conversion steps, having applied successfully to the propylene carbonate production case. In this work, a systematic evaluation of all representative cyclic carbonate literature was made, covering ethylene, propylene, butylene, hexylene, cyclohexene, and styrene cyclic carbonates, in order to guide the product role within the integrated CCU (ICCU) concept. The multiscale strategy combining molecular simulation (DFT -Density Functional Theory-, COSMO -COnductor-like Screening MOdel-), process simulation (COSMO/Aspen methodology), and life cycle assessment (LCA) was used to set up, simulate and evaluate the processes. ICCU configuration is the best approach when compared with sequential configuration for energy consumption analysis (reduction of 28, 28, 22, 11 and 6 %, respectively, for ethylene, propylene, butylene, hexylene, and cyclohexene cases) and CO2 emissions associated (reduction of 38, 40, 31 and 14 %, respectively, for ethylene, propylene, butylene, and hexylene cases). The main variable of the results is the boiling point of the cyclic carbonate since heavy products impose technical limitations and even discard ICCU alternative. The ICCU concept works since all cyclic carbonates’ reaction enthalpies are higher than that of the IL-CO2 one, which reduces heating requirements. Finally, energy demand can be slightly further reduced, partially recycling the cyclic carbonate to the capture unit.

Fast and sustainable CO2 conversion to propylene carbonate using fluoroalcohol-based bifunctional ionic liquids: Insights from experiments and theoretical simulations

We report on the metal-free and rapid catalytic conversion of carbon dioxide into cyclic carbonates under solventless conditions utilizing novel bifunctional fluoroalcohol-based ionic liquids (FBILs) as catalsyts. In the presence of 2.5 mol% 4-(1,1,1,3,3,3-hexafluoro-2-hydroxyisopropyl) phenyl trimethylammonium iodide (FBIL-1), under 0.1 MPa and 90 °C, excellent yield of propylene carbonate(>95%) was achieved in 1 h, which significantly shortens the reaction time, compared with the conventional catalysts. DFT calculations reveal that FBILs with fluorine-substituted hydroxyl groups exhibit stronger hydrogen bonding with epoxides compared to ILs lacking fluorine substitutions. The hydrogen bond length for ILF/PO is 1.658 Å, shorter than that for IL/PO (1.813 Å). This characteristic contributes to reducing the activation energy for the ring-opening reaction of epoxides. In the ILF/PO system, the reaction barrier is 88.72 kJ·mol−1, lower than the 101.46 kJ·mol−1 barrier for IL/PO, allowing the former to more rapidly facilitate the fixation of carbon dioxide into cyclic carbonates. Besides high catalytic efficiency, these FBILs have the characteristics of a facile synthesis route and easy post-reaction recovery.

A novel bifunctional ionic liquid [N1888][OOB] for the separation of rare earth and transition metal in NdFeB magnet

In this paper, a series of novel bifunctional ionic liquids with methyltrioctylammonium as the cation and o-alkoxybenzoic acetate as the anion were synthesized. Their extraction properties were investigated for the separation of rare earth and transition metal for NdFeB waste recycling. It was found that [methyltrioctyl ammonium][o-octyloxybenzoic acetate] ([N1888][OOB]) could preferentially extract rare earth while the extraction abilities of Fe and Co were weak. The extraction mechanism of rare earth with [N1888][OOB] was indicated to be ion association in a molar ratio of 2:1. The rare earth loaded by [N1888][OOB] could be selectively stripped with water. Based on the above research results, a novel separation process was developed to separate rare earth, Fe and Co with [N1888][OOB]. This study intensified the separation process of rare earth and transition metals. The novel separation strategy based on [N1888][OOB] has revealed the advantages of efficiency and sustainability for rare earth recovery.

A green method for the synthesis of lubricating ester oil using a bi-functional ionic liquid

An ionic liquid [BTAMIM][DEPH] was prepared that could not only catalyze the synthesis of ester oil with good catalytic activity but also serve as a lubricant additive, which improved the friction reduction and anti-wear performance of the ester oil.

Efficient dimerization of perfluoroolefin catalyzed by strong nucleophilic bifunctional ionic liquids

Ionic liquid, as a green and efficient nucleophilic catalyst, shows great potential in the dimerization of perfluoroolefin, which further promotes the greening of the fluorine chemical reaction process.

Phenoxy-Nitrile Bifunctional Ionic Liquid for Efficient Electroreduction of CO2 to Oxalate

Phenoxy-Nitrile Bifunctional Ionic Liquid for Efficient Electroreduction of CO₂ to Oxalate

Sterically regulated halogen‐free bifunctional ionic liquids for catalytic conversion of CO2 into cyclic carbonates

AbstractIn the cycloaddition reaction of carbon dioxide (CO2) with epoxides, halogen catalysts lead to halogen loss and environmental pollution. It is necessary to design efficient and environmentally friendly catalysts. A series of halogen‐free phosphonium ionic liquids (ILs) regulated by steric hindrance were designed and synthesized. It is further used as effective catalysts for the catalytic conversion of CO2 into cyclic carbonates. The effect of different catalyst structures on catalytic activity has been investigated. Amino group has been shown to contribute to increased activity, and its location determines the degree of increased activity. Among them, [Bu4P]2[5‐AMP] with meta‐substitution showed the best catalytic activity, the conversion of propylene oxide (PO) was 96 % at the optimum conditions of 120 °C, 2 MPa and 3 h. Based on characterization analysis and DFT calculations, the interaction of ILs with CO2 and PO were revealed. Finally, a plausible synergistic catalytic mechanism was proposed. The halogen‐free, metal‐free phosphonium ILs proposed in this paper provide a new insight on catalyst design and CO2 utilization.

Magnetic ionic liquid catalyst functionalized with antimony (III) bromide for effective glycolysis of polyethylene terephthalate

In a previous study, we demonstrated the efficient depolymerization of polyethylene terephthalate (PET) through glycolysis using antimony (III) oxide, a commonly used catalyst in PET synthesis. In the present research, we introduce a novel approach involving the synthesis of a magnetic bifunctional ionic liquid, Fe3O4@PMIM.SbBr4, containing only 2.2 wt% of antimony. The aim is to reduce the required antimony dosage for the reaction and enable its facile recovery and reuse. By employing this catalyst in PET chemical recycling through glycolysis to generate bis (2-hydroxyethyl) terephthalate (BHET) monomer, we achieved 100% PET conversion with a 96.4% yield and selectivity for BHET. This outcome was obtained using a catalyst loading of 6.0 wt% at 200 °C and 0.6 bar in a high-pressure reactor. We explored the impact of catalyst loading on BHET yield and conducted a comparative assessment of the Fe3O4@PMIM.SbBr4 catalyst against antimony (III) bromide, and another synthesized unsupported antimony-containing ionic liquid. Our results revealed the superior catalytic activity of the magnetic ionic liquid catalyst in PET glycolysis. The utilization of this catalyst offers promising potential for PET glycolysis due to its effortless separation using an external magnet, ability to produce highly pure BHET, and recyclability for repetitive use.

Complex extraction of rare earth elements from nitrate solutions with a tri-n-octylamine-octanoic acid bifunctional ionic liquid

In this work, a new hydrophobic bifunctional ionic liquid based on tri-n-octylamine and octanoic acid was synthesised and a physicochemical characterisation was performed on it. The extraction of a series of rare earth elements (Y, Eu, Gd, Tb) (REEs) from aqueous nitrate solutions in a system containing the resulting ionic liquid was studied. Extraction isotherms were obtained and regularities of the interphase distribution of REEs were determined as a function of extraction process time, NaNO3 concentration, the pH of the aqueous phase, the concentration of the ionic liquid in the system, the volume ratio, and temperature of the process. It was shown that the extraction of REEs nitrates by the ionic liquid based on tri-n-octylamine and octanoic acid occurred in accordance with the mechanism of binary extraction of salts with the formation of two extractable compounds in the organic phase. In addition, this IL has been shown to exhibit excellent reusability.

A Bifunctional Ionic Liquid for Capture and Electrochemical Conversion of CO2 to CO over Silver.

Electrochemical conversion of CO2 requires selective catalysts and high solubility of CO2 in the electrolyte to reduce the energy requirement and increase the current efficiency. In this study, the CO2 reduction reaction (CO2RR) over Ag electrodes in acetonitrile-based electrolytes containing 0.1 M [EMIM][2-CNpyr] (1-ethyl-3-methylimidazolium 2-cyanopyrolide), a reactive ionic liquid (IL), is shown to selectively (>94%) convert CO2 to CO with a stable current density (6 mA·cm-2) for at least 12 h. The linear sweep voltammetry experiments show the onset potential of CO2 reduction in acetonitrile shifts positively by 240 mV when [EMIM][2-CNpyr] is added. This is attributed to the pre-activation of CO2 through the carboxylate formation via the carbene intermediate of the [EMIM]+ cation and the carbamate formation via binding to the nucleophilic [2-CNpyr]- anion. The analysis of the electrode-electrolyte interface by surface-enhanced Raman spectroscopy (SERS) confirms the catalytic role of the functionalized IL where the accumulation of the IL-CO2 adduct between -1.7 and -2.3 V vs Ag/Ag+ and the simultaneous CO formation are captured. This study reveals the electrode surface species and the role of the functionalized ions in lowering the energy requirement of CO2RR for the design of multifunctional electrolytes for the integrated capture and conversion.

Bi-functional ionic liquid based on Aliquat 336 and Cyanex 572 for effective separation of Nd(III) and Ni(II) from chloride solution and recover Nd2O3 from waste Nd-Ni-Fe magnets

The recovery of lanthanide elements is considered a vital sector in the field of spent nuclear fuel reprocessing. The current paper describes a novel method for recycling a real scrap NdFeNi magnet from computer hard disks in order to recover Nd(III) as a marketable salt and other valuable by-products while also establishing an environmentally friendly process.Solvent extraction of Nd(III) and Ni(II) ions with the synthesized bi-functional ionic liquid (Bif–IL) based on Aliquat 336 and Cyanex 572 [AL336][Cy572] in kerosene was systematically investigated in a chloride solution. When compared to Cyanex 572 alone, Bif–IL improved not only the extraction percentage of these metal ions but also the separation factors between Nd(III) and Ni(II). The effects of different parameters on the extraction process, as well as thermodynamic parameters, were investigated. Based on the slope analysis method and the IR–spectrum, the extracted species are NdCl3(R4NCy)3(org) and NiCl2(R4NCy)2(org) for the studied metal ions. Following that, the loaded organic phase was successfully stripped for Nd(III) ions with 0.5 mol/L HCl. The McCabe–Thiele diagram was used to determine the number of stages required for the extraction and stripping of Nd(III) ions. Eventually, the separation of Nd(III) from scrap NdFeNi magnet leach liquor demonstrates the efficacy of the suggested process.

Evaluation of extraction behaviour of techno metal neodymium from nitrate feed using Tri-n-hexylamine di-2-ethyl hexyl phosphate as extractant

The rare earths are presently considered as the critical elements by the European Union. High technological use of neodymium as neodymium-iron-boron permanent magnet resulted in more demand and dearth of supply of this rare earth. This has initiated efforts on an urgent basis to find alternative resources for potential recovery of neodymium. This present investigation focuses on study of the extraction profile of neodymium from the aqueous nitrate feed using a bifunctional ionic liquid comprised of trihexylamine di-2-ethyl hexyl phosphate in kerosene. The variations in shaking time, salt concentration, aqueous phase pH, diluting agents, Nd3+ concentration, temperature were performed in order to know their impact on the extraction were analyzed. Results indicated that the extraction percentage increases when salt concentration as well as with extractant concentration increased. Extraction becomes 99.1% with 2 M NaNO3 at pH 3 using 0.1 M of the ionic liquid. Increase in the aqueous feed pH also increased extraction percentage while temperature showed negative impact. The amine based ionic liquid has been found as a potential extractant for Nd extraction from nitrate medium.

One-step extraction and solidification of uranium (VI) from sulfate leaching liquor using bifunctional ionic liquids

Three bifunctional [DODMA]+[DGA]- ionic liquids were synthesized starting from [DODMA]+[Cl]- surfactant and N, N-dialkyl-diglycolamide acid (DGA), which were employed for extraction of U(VI) from real leach solution. The simultaneous purification and solidification of uranium (VI) were realized in one-step process in sulfuric acid medium, and the extracted solid captured more than 99 % uranium (VI) was found to aggregate at the biphasic interface. XPS, FT-IR, ESI-MS and TGA analysis revealed that U(VI) ions were assembled into uranium-containing solids by coordination of uranyl ions and dicarbonyl groups of [DGA]- anions using amphiphilic property of [DODMA]+ cations. An unusual multi-step extraction mechanism by anionic exchange was proposed to elucidate the excellent selectivity for U(VI). The present bifunctional ionic liquids exhibited the high affinity for U(VI) compared to 18 main elements assayed in ore leaching liquor. The key interfering ions such as Fe(III) and V(V) were hardly extracted to enrich in the extracted solid, and the good separation factors were obtained in 280 for U/Fe and 117 for U/V. Without further back-extraction, final precipitation and other relevant operation, the proposed one-step strategy was considered as a sustainable or promising process for easier recovery of U(VI) in sulfate leaching liquor.

Amine/Carboxylic Acid Based Bifunctional Ionic Liquids as Extractants for Nd(III), Sm(III) and Eu(III) from Aqueous Solution Containing EDTA

AbstractTwo bi‐functional ionic liquid extractants (Bif‐ILs) comprising tertiary amine and carboxylic acids, namely [TOAH]+[OHex]− (Tri‐n‐octylaminehexanoate) and [TOAH]+[ODec]− (Tri‐n‐octylaminedecanoate) in kerosene have been used for extraction of Nd(III), Sm(III) and Eu(III) from aqueous phase with EDTA as a complexing agent. The extraction ability of both the extracting agents has been analyzed with respect to variations in shaking time, concentration of extractant, aqueous phase pH, molarity of EDTA, diluents and phase volume ratio. Using 0.08 mol/L EDTA,extraction of Nd(III) was maximum with both the extractants followed by Sm(III) and Eu(III).At 4 : 1 (O/A) phase volume ratio, the extraction percentages using [TOAH]+[OHex]− were 93.42 % (Nd), 89.83 % (Sm), 84.14 % (Eu) and with [TOAH]+[ODec]− the values were 90.42 % (Nd), 89.37 % (Sm), 83.65 % (Eu), respectively.Extraction efficiency of both Bif‐ILs is maximum for Nd(III). Stripping was quantitative with HNO3 and HCl.Speciation studies and FTIR spectra provide valuable information regarding the stoichiometry of the extracted species.

Extensive investigation on extraction behaviour of organo-phosphrous based bi-functional ionic liquids for separation of molybdenum (Mo) from spent Co-Mo/Al2O3 leach liquor

The sulphate mediated spent catalyst Co-Mo/Al2O3 leached liquor bearing ∼ 6.05 g/L of Mo, 1.75 g/L of Al and 1.44 g/L of Co was subjected to the solvent extraction separation of Mo using noble bi-functional ionic liquids (BILs). Comparative extraction behaviour of Mo with two BILs such as quaternary ammonium D2EHPA(R4ND) and quaternary ammonium Cyanex 272 (R4NCY) synthesized from Aliquat 336 in combination with D2EHPA and Cyanex 272 was systematically investigated. The purity of synthesized ILs was ascertained from NMR analysis. The role of both BILs concentrations appears to be critical on extraction of Mo at acidic pH ranges of the solution with an association of 1 mol each as evident from slope analysis equilibrium study. The Extraction of Mo as H2MO4 at optimum solution pH of 2.0 gives rise to achieve a selective separation of Mo in presence of Co and Al as ensured from separation factor (S.F.) value; βMo/Co = 5388.8 and 1642.5 for R4ND and R4NCY and βMo/Al = 1309.2 and 13522.1 for R4ND and R4NCY respectively. The extraction yield of Mo with ILs was enhanced while increasing the temperature of the solution as indicated from the positive ΔH (+40.26 KJ/mol & 73.27 βMo/Co = 5388.8 and 1642.5 for R4ND and R4NCY and βMo/Al = 1309.2 and 13522.1 for R4ND and R4NCY) values. The diluents effect on Mo extraction was consistent with either of the ILs and they follows the order as n-Hexane > Tolune > Kerosene > Benzene > Xylene. The Mc-Cabe Thiele plot constructed at A: O = 5:1 has predicted 2 stages using 0.6 M each of R4ND and/or R4NCY and later it was validated from CCS leading to attain>99.9 % Mo extraction. The extraction behaviour of R4NCY was efficient and effective on clean separation of Mo over R4ND at the studied experimental condition. Stripping of Mo-loaded-R4NCY by NH4OH was promising with the Mo enrichment up to 3 times with generation of purified stripped bearing 90.71 g/L of Mo. FTIR characteristic peak of R4ND and R4NCY before and after extraction confirms in support of the Mo extraction with ILs. The purity of synthesized ILs was ascertained from NMR analysis.

DDQM][HSO4]/TBHP as a Multifunctional Catalyst for the Metal Free Tandem Oxidative Synthesis of 2-Phenylquinazolin-4(3H)-ones.

A bifunctional ionic liquid (IL) [DDQM][HSO4] has been designed and explored as a three-way catalyst for the synthesis of 2-phenylquinazolin-4(3H)-ones from anthranilamide and benzyl alcohol in 3.5 min incorporating microwave irradiation. Photochemically the reaction proceeds for 4 h at room temperature and thermally for 8 h at 120 °C. Further IL-assisted metal, solvent, and base free in situ oxidation of benzyl alcohols to aldehydes shows its task specificity. The multifunctionality of the IL was reestablished with the synthesis of two Wnt pathway antagonists.