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Recently, pharmaceuticals and personal care products in the water environment exhibited potential risks to both human and aquatic organisms. In order to improve the sensitivity and accuracy of pharmaceutical detection, the polyimidazolyl acetate ionic liquid was synthesized by Radziszewski reaction and coated on cellulose filter papers as a thin‐film extraction phase for extraction of non‐steroidal anti‐inflammatory drugs from water. The attenuated total reflection‐infrared spectrometry, thermogravimetric analysis, and scanning electron microscope analyses demonstrated that the polyimidazolyl acetate ionic liquid was successfully prepared and attached to the surface of the cellulose filter paper through chemical bonding. The adsorption capacity of the homemade thin‐film extraction material for the four non‐steroidal anti‐inflammatory drugs was greater than 8898 ng/cm2 under the optimum conditions, and the desorption rate was over 90%. Then, a paper‐based thin‐film extraction phase‐high‐performance liquid chromatography‐tandem mass spectrometry method was established for the extraction of non‐steroidal anti‐inflammatory drugs in water. This method provided limits of detection and limits of quantification were in the range of 0.02–0.15 and 0.17–0.50 μg/L, respectively. Hence, the obtained thin‐film extraction phase showed excellent recovery and reproducibility for the target non‐steroidal anti‐inflammatory drugs with carboxyl groups from water. [ABSTRACT FROM AUTHOR]

A simple and large‐scale non‐chemical preparation of uniform poly(ionic liquid) (PIL) microbeads via a cooling‐assisted phase separation (CAPS) method is reported. For this method, PIL bulk is dissolved to form a saturated solution in a mixed solvent composed of good solvent and non‐solvent at a relatively high temperature. Then, the uniform PIL microbeads are prepared by cooling the solution to room temperature or a lower temperature in the absence of stabilizer. The size of microbeads can be controlled by adjusting the preparation parameters, including PIL concentration, cooling rate, and agitation state. The scale of preparation can be up to 10 g, and the yield of PIL microbeads is more than 70% or 88% when the solution is cooled to room temperature or 0 °C, respectively. The formation mechanism of PIL microbeads is discussed by tracing the nucleation and growth process by the transmittance of light of the solution during cooling. The application of this CAPS method to other polymer microbeads preparation is finally discussed by choosing different good solvent and non‐solvent. [ABSTRACT FROM AUTHOR]

Self-crosslinked bis(imidazolium)-based poly(ionic liquid)s (PILs) containing different counterions (P[C 2 DVIM][X], X = BF 4 −, PF 6 −, TfO−, TFSI−) are synthesized and the influence of counterions on electro-responsive electrorheological (ER) effect is studied in order to understand the structure-property relationship of crosslinked PIL-based ER system. It is found that the size and type of counterions have a significant influence on ER effect. As the size increases, the ER effect decreases (i.e. BF 4 − > PF 6 − > TfO− > TFSI−). Different from the linear PIL-based ER system, however, the P[C 2 DVIM]X with inorganic counterions shows stronger ER effect compared to P[C 2 DVIM]X with organic counterions. Meanwhile, the influence of counterions on temperature dependence of ER effect of the crosslinked PIL system is also different from the linear PIL system. By dielectric spectroscopy and X-ray scattering measurements, the mechanism behind the influence is analyzed. It demonstrates that, different from linear PIL system, the ionic aggregation is largely weakened in P[C 2 DVIM]X and the transport of mobile counterions and interfacial polarization are mainly dominated by the mesh size of crosslinking network. This should be responsible for the different dependence of ER effect on the size and type of counterions between self-crosslinked and linear PIL systems. Different from linear poly(ionic liquid), self-crosslinked poly(ionic liquid)s (P[C 2 DVIM]X) with inorganic counterions show stronger ER effect compared to P[C 2 DVIM]X with organic counterions (i.e. BF 4 − > PF 6 − > TfO− > TFSI−). This is related to the fact that, instead of ionic aggregation, the mesh size of crosslinking network dominates the ion transport and interfacial polarization of self-crosslinked poly(ionic liquid)s. Image 1 • Self-crosslinked PILs (P[C2DVIM]X) with different counterions are synthesized. • Influence of counterions on ER effect of P[C 2 DVIM]X differs from linear PILs. • P[C 2 DVIM]X with inorganic counterions show higher ER effect than that with organic counterions. • Mesh size of crosslinking network rather than ionic aggregation dominates polarization and ER effect of P[C 2 DVIM]X. [ABSTRACT FROM AUTHOR]

Different from classic polyelectrolytes, poly(ionic liquid)s (PILs) bearing hydrophobic counterions show high electrorheological (ER) effect in dry state. This opens a way to develop new generation of anhydrous polyelectrolyte ER fluids. However, PILs with linear backbone are limited in practical applications due to low glass transition temperature. Crosslinking is an effective method to overcome this problem but the structure-property relationship in crosslinked PIL ER system is not fully understood. Herein, a family of self-crosslinked poly(bis-vinylimidazolium bis(trifluoromethane sulfonylimide))-based PILs with different length of alkyl spacer (P[C n DVIM][TFSI]) were synthesized. The influence of alkyl spacer length on ER effect was studied and the influence mechanism was analyzed by combination of rheology, dielectric spectroscopy and X-ray scattering measurements. It shows that as alkyl spacer length increases, the ER effect increases but the working temperature range becomes narrow. This is related to the fact that the length variation of alkyl spacer alters the mesh size of crosslinking network of P[C n DVIM][TFSI], which further influences the transport dynamic of mobile counterions and ion motion-induced interfacial polarization. Self-crosslinked poly(ionic liquid) particles with different length of alkyl spacer are synthesized, which show increased ER effect but narrowed working temperature range with increasing alkyl spacer length because increasing the mesh size of crosslinking network decreases the potential energy barrier for ion transport and ion motion-induced interfacial polarization but easily causes current leakage at high temperature. Image 1 • Self-crosslinked PILs with different length of alkyl spacer are synthesized. • As spacer length increases, ER effect of PILs increases but working temperature range becomes narrow. • Spacer length influence is because mesh size of crosslinking network influences ion transport and interfacial polarization. [ABSTRACT FROM AUTHOR]

Nitrogen‐doped carbons supported gold catalysts has attracted much attention in a broad range of applications. However, co‐existence of multiple nitrogen species which may have vastly different effect on the gold‐based catalysts, has limited the development of an ideal nitrogen‐doped carbon support. Herein, we have demonstrated that by addition of sulfur species, selective formation of pyrrolic nitrogen against pyridinic nitrogen can be achieved for pyrrolic nitrogen doped carbon support. The gold catalysts synthesized from the pyrrolic nitrogen doped carbon support produced using ionic liquid‐assisted synthetic strategy (Au/N, S‐AC‐700), exhibited excellent catalytic activity and stability for hydrochlorination of acetylene. The outstanding performance was attributed to the π electrons transferred from pyrrolic nitrogen to Au (III) center, which could increase the electron density of Au hence facilitate the adsorption of hydrogen chloride on the catalyst. Green economy? Carbon with surface‐enriched nitrogen and sulfur supported Au catalysts was developed for acetylene hydrochlorination. The presence of sulfur species on the carbon surface inhibited the formation of pyridinic N which was not necessary for the hydrochlorination of acetylene. [ABSTRACT FROM AUTHOR]

High-valent Au(III) complexes have attracted much attention as catalysts in many reactions. Nevertheless Au(III) catalysts suffer from instability of the oxidized metal complexes during preparation and use. Herein, we demonstrated that Au(III) catalysts can be stabilized against reduction to metallic Au 0 by modifying supported-ionic-liquid-phase-stabilized Au(III) catalyst with CuCl 2 . It was found that the that reduced Au 0 could be re-oxidized in situ to Au 3+ species by CuCl 2 during the reaction and further stabilized by the electron transfer from Cu to these active species. When evaluated in the acetylene hydrochlorination reaction, the Au-Cu-IL/AC catalyst displayed an excellent specific activity with the turnover frequency (TOF) as high as 168.5 h −1 and more than 99.8% selectivity for the product, vinyl chloride (VCM). Furthermore, the Au-Cu-IL/AC catalyst demonstrated a stable catalytic performance with a negligible loss of C 2 H 2 conversion after 500 h under typical industrial reaction conditions for acetylene hydrochlorination. Therefore, the findings of this work provide an efficient approach for designing stable high-valent metals for long-term operation, and also pave the way for the application of Au-Cu-IL/AC catalyst in industrial VCM production. [ABSTRACT FROM AUTHOR]

A novel 1-[3-(tert-butoxycarbonylamino)propyl]-3-[3-(N-pyrrole)propyl]imidazolium tetrafluoroborate ionic liquid was successfully synthesized and was used as functional monomer to electrochemically fabricate a polymer film modified glassy carbon electrode (Poly-IL/GCE). Morphology and the interfacial property of Poly-IL/GCE were examined with scanning electron microscope and electrochemical impedance spectroscopy, respectively. Bisphenol A (BPA) was chosen as a model compound to investigate the sensing performance of Poly-IL/GCE using voltammetry. The oxidation peak currents of BPA at the Poly-IL/GCE exhibit a linear response to its concentration in the range of 1.0 × 10-1.0 × 10 M. The detection limit is calculated to be 4.0 × 10 M (S/N = 3). The Poly-IL/GCE was successfully applied to analysis BPA leaching from drinking water bottle. The results are consistent with that of high-performance liquid chromatography. [ABSTRACT FROM AUTHOR]

Poly(ionic liquid)s are providing potential platforms to develop new generation of water-free polyelectrolyte-based electorheological materials due to strong polarizability and intrinsic hydrophobicity. To enhance polarization and electro-response by employing combined contribution of ion number density and ion transport dynamic, we here have developed a kind of di-ionic poly(ionic liquid)s for use as new electorheological materials. It has found that di-ionic poly(ionic liquid)s have enhanced electorheological effect compared with common mono-ionic poly(ionic liquid)s but enhancement degree depends on counterion type. The enhancement of di-ionic poly(ionic liquid)s with PF 6 − as counterions is more significant than those with TFSI− as counterions. By combining dielectric spectra with Raman and X-ray scattering analyses, it has demonstrated that enhanced electorheological effect of di-ionic poly(ionic liquid)s is because di-ionic structure can increase interfacial polarization by combined contribution of enhanced ion number density and transport dynamic. However, the enhancement degree is more significant for PF 6 − than TFSI− due to its small size and low plasticizing capacity. Compared to common mono-ionic poly(ionic liquid)s, di-ionic poly(ionic liquid)s show enhanced electro-responsive electrorheological effect because di-ionic structure can increase the interfacial polarization by the combined contribution of enhanced charge density and ion transport dynamic. Image 100 • Di-ionic PIL particles are synthesized for use as new PIL-based ER materials. • Di-ionic PILs show enhanced ER effect than mono-ionic PILs. • ER enhancement of di-ionic PILs with PF 6 − is more obvious than those with TFSI−. • Enhanced ER effect is because di-ionic structure increases interfacial polarization. • Enhanced polarization is due to increased charge density and transport dynamic. [ABSTRACT FROM AUTHOR]

A systematic study of the kinetics of supported-ionic-liquid-phase (SILP) Au catalysis (Au-IL/AC) has been established in the continuous gas-phase hydrochlorination of acetylene. We reveal that the effect of ionic liquid (IL) film on substrate diffusion can be eliminated. The reaction order of the catalyst indicates that Au is confirmed to exist as a monomer in the IL film of the Au-IL/AC system, which is different from the fast equilibrium of the "Au dimer and monomer" for the classical Au/AC catalyst. The homogeneous reaction micro-environment is confirmed for Au-IL/AC since the activation energy was little changed under both heterogeneous and homogeneous catalysis, further verifying the monatomic characteristics of Au in Au-IL/AC. Due to the supported IL film, the reaction order of hydrogen chloride was decreased from 1 to 0.5 while creating a hydrogen chloride enrichment system around Au, which provides the possibility of producing vinyl chloride with an equal substrates feed ratio. This kinetic-perspective-based revelation of the catalytic behavior of the metal active sites confined in IL film enriches and expands the SILP catalytic system for acetylene hydrochlorination. [ABSTRACT FROM AUTHOR]

The electrochemical NRR, which can be driven by renewable energy sources, is an emerging strategy for addressing the high energy consumption and CO 2 emission issues caused by the traditional Haber–Bosch ammonia synthesis technique. FePc catalyzes the electrochemical ammonia synthesis reaction well, but intermolecular π-stacking and multi-layer overlapping lead to low NH 3 yields. Here, [Bmim][Cl] and [Bmim][NTF 2 ] ILs were used to induce monolayer dispersion of FePc. Ionic-liquid-induced FePc electrocatalyst, namely FePc/C-700, which was constructed with ILs as the carbon source, gave an excellent NH 3 yield (24.25 μg mg cat −1 h−1) and Faradaic efficiency (30.59%) at − 0.1 V. The formation of a monolayer FePc structure was confirmed by HAADF-STEM and XANES. The results of DFT calculations and NRR experiments showed that the monolayer FePc structure promoted N 2 adsorption and inhibited the competitive HER. These results will be useful in the design of active sites of layered macromolecules to achieve efficient electrochemical NRR. [Display omitted] • The monolayer FePc/C-700 catalysts successfully synthesized in this work exhibits excellent catalytic activity in the NRR. • Using ILs to induce monolayer dispersion of FePc and as carbon sources to suppress the formation of multi-layer FePc structure • This work proves that the formation of the multi-layer FePc structure affects the activation of N 2. [ABSTRACT FROM AUTHOR]

An ionic liquid [dibmim]Cl with a dedicated electron pathway for electron stripping were designed and synthesized for metal dissolution which exhibited high metal dissolution rate for Au, Pd, and Cu, the recollected and recycled ionic liquid showed consistent metal leaching yields for 5 cycles. The metal dissolution mechanism was also exposed according to experimental and calculational results. [Display omitted] • Task-specific ionic liquid for highly efficient Au, Pd, Cu dissolution. • Rational design and construction of electron pathway in cation for electron stripping from metal nanoparticles. • Environmental benign dissolution system for metal recovery from secondary sources. A task-specific ionic liquid ([dibmim]Cl) showing a high dissolution rate for noble metals was reported herein, and the dissolution mechanism of Pd as representative of noble metals, was deduced from a series of characterization. The electron stripping and dissolution mechanism process was further verified using DFT calculation. [ABSTRACT FROM AUTHOR]

Enhancement of the sulfur resistance of gold-based catalysts is significantly relevant and highly desirable for the development and large-scale applications of these catalysts. In this study, a supported gold-based imidazolium ionic liquid catalyst was shown to be ultra-high resistant towards sulfur poisoning during the acetylene hydrochlorination reaction. To explore the impact of H2S on the as-prepared catalysts, accelerated laboratory-scale poisoning tests were performed, and characterization was achieved by various instruments. The adsorption of H2S on the active sites of Au/AC catalysts, occupying gold species, prevented the reactants, including C2H2 and HCl, from being adsorbed on the catalyst surface. With respect to the Au–IL/AC catalysts, the unique Au–IL colloid complexes, formed from ionic liquids, impart resistance towards H2S; moreover, the ionic liquid layer on the activated carbon surface can prevent the deposition of sulfur impurities on catalysts; in addition, the adsorption of H2S on the ionic liquid layer is a dynamic equilibrium process, and the adsorption equilibrium constant at 180 °C (453 K) is 0.24 L mg−1. The interaction between H2S and the ions in the ionic liquid is weaker than the binding force within ions in the ionic liquid itself. [ABSTRACT FROM AUTHOR]

By using different conductivity of polyaniline as filler, a kind of poly(ionic liquid)/polyaniline composite particles was synthesized to investigate the influence of dielectric polarization rate difference between filler and matrix on the electrorheological response and flow stability of composite-based electrorheological fluids under simultaneous effect of shear and electric fields. The composite particles were prepared by a post ion-exchange procedure and then treated by ammonia or hydrazine to obtain different conductivity of polyaniline. Their electrorheological response was measured by dispersing these composite particles in insulating carrier liquid under electric fields. It showed that the composite particles treated by ammonia had the strongest electrorheological response and most stable flow behavior in a broad shear rate region from 0.5 s−1 to 1000 s−1. By using dielectric spectroscopy, it found that the enhanced electrorheological response with stable flow depended on the matching degree of the dielectric polarization rates between poly(ionic liquid) matrix and polyaniline filler. The closer their polarization rates are, the more stable the flow curves are. These results are helpful to design optimal composite-based electrorheological materials with enhanced and stable ER performance. [ABSTRACT FROM AUTHOR]

Modified and stabilized palladium nanoparticles were prepared successfully by using an ionic liquid, 1-butyl-3-methylimidazolium trifluoroacetate. Activated carbon was used as a support for the palladium catalyst. Instead of using hydrogen gas, the Pd-catalyzed hydrodechlorination (HDC) reaction in this study used aqueous formic acid–formate buffer solutions as a hydrogen source due to its non-flammability. The results showed that both the ionic liquid and active carbon support facilitate the Pd active center to effectively carry out the catalytic HDC reaction of 4-chlorophenol (4-CP). The ionic liquid (IL) played a dual role as both a solvent and co-factor to facilitate the reaction. The IL would stabilize, better disperse, and prevent the congregation of palladium nanoparticles. On the other hand, active carbon provides a stronger binding site for stabilizing the active Pd centers. The catalytic HDC reaction indicated that the turn over frequency (TOF) of ionic liquid with a reduced catalyst was about 5–6 times higher than that of the non-ionic liquid mediated catalyst. This excellent catalytic activity suggested that the ionic liquid is dispersing nanoparticles effectively, preventing the creation of Pd nanoparticle clusters through the strong interaction of Pd species with the ionic liquid (IL). This IL-Pd interaction helped to form a protection layer to stabilize the Pd active centers. This study also confirmed that both the Pd0 and Pdn+ states were required for the catalytic HDC reaction. Furthermore, the Pd-catalyst was characterized by different techniques such as Brunauer–Emmett–Teller (BET) surface area analysis, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FT-IR). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Supported-ionic-liquid-phase was introduced to enhance the selectivity of ethylene in the semi-hydrogenation of acetylene. • Unique Carbene structure derived from ionic liquids was found to be beneficial to the ethylene selectivity. • The Carbene structure was evidenced by C1s and N1s XPS spectra. • Carbene is able to enrich the electron density of palladium, which facilitates the desorption of ethylene. Abstract Designing the electron-rich palladium active site is of great importance to enhance the selectivity of ethylene in acetylene semi-hydrogenation. In this work, ionic liquids, the effective electronic modifier, were mingled with palladium solution to be immobilized on Al 2 O 3 by incipient impregnation method. X-ray photoelectron spectra characterization was conducted to characterize the structure of catalysts, suggesting that some ionic liquids can form unique carbene structure. The catalytic results showed that those immobilized ionic liquids that can form unique carbene structure exhibited much higher selectivity of ethylene than those cannot. The above results were obtained because carbene can donor the electron to palladium, enriching the electron density of palladium and therefore facilitating the desorption of ethylene. The findings of the unique carbene structure derived from ionic liquids in this work provide an efficient strategy to design the catalyst to improve the selectivity of the intermediate in other partial hydrogenationreactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A facile strategy for controlling the liquid–solid interface of Cs sites is developed by supported ionic liquid (IL) phase. • Cs sites are stabilized via the electrostatic effect with IL anions. • IL promotes the activation of TCE and enhances the desorption of HCl. • The thermodynamic generation process of VDC is promoted within the supported IL phase. There remain considerable challenges for Cs-based catalysts in gas-phase dehydrochlorination of 1,1,2-trichloroethane (TCE) due to their poor catalytic performance and harsh reaction temperature requirements. In this work, we report a novel supported ionic liquid (IL) phase Cs-based system and evaluate its catalytic performance and mechanism, combining the kinetic and DFT calculations. The optimal Cs-IL/SiO 2 catalyst achieved the TCE conversion of 60% and the selectivity to 1,1-Dichloroethylene (VDC) of 86% under the mild temperature of 200 °C. It is demonstrated that IL additives can significantly improve the dispersion of Cs species during the catalyst preparation and evaluation process. Moreover, IL promotes the activation of TCE and enhances the desorption efficiency of HCl, which is the main reason for its high activity. The selectivity is improved by changing the adsorption behaviors of the products, which ensures the preferential formation of the main product VDC. The enhanced activity and selectivity of Cs-IL/SiO 2 suggest a promising candidate for dehydrochlorination reaction. [ABSTRACT FROM AUTHOR]

Adsorption and activation for substrates and the stability of Pd species in Pd-based catalysts are imperative for their wider adoption in industrial and practical applications. However, the influence factor of these aspects has remained unclear. This indicates a need to understand the various perceptions of the structure–function relationship that exists between microstructure and catalytic performance. Herein, we revisit the catalytic performance of supported-ionic-liquid-phase stabilized Pd-based catalysts with nitrogen-containing ligands as a promoter for acetylene hydrochlorination, and try to figure out their regulation. We found that the absolute value of the differential energy, |Eads(C2H2)-Eads(HCl)|, is negative correlated with the stability of palladium catalysts. These findings imply that the optimization of the electron structure provides a new strategy for designing highly active yet durable Pd-based catalysts. [ABSTRACT FROM AUTHOR]

We studied the acetylene hydrochlorination in gas–liquid phase reactions using ionic liquids (IL) as the reaction media and CuCl2 as the catalyst. The Cu-IL catalyst showed strong synergy between the IL and the Cu(II) active catalytic species. For [PrMIm]Cl, the Cu-IL catalyst exhibited significant enhancement of the catalytic activity in comparison with the CuCl2 catalyst supported on activated carbon and the IL alone as the catalyst. We have also performed DFT calculations of the reaction process, which provides a good explanation of our experimental results and for the synergetic effect. Our result suggests that ILs may be used to improve the activity of other metallic catalysts for the hydrochlorination reaction of acetylene. [ABSTRACT FROM AUTHOR]