3-sulfonic Group Research Articles

Selective Production of Glycolic Acid from Cellulose Promoted by Acidic/Redox Polyoxometalates via Oxidative Hydrolysis

The direct conversion of cellulose to glycolic acid (GA) with a high yield of up to 75% is realized using acidic/redox polyoxometalates (POMs) as catalysts in a one-pot reaction. Analysis of the reaction pathway and mechanism for the three POMs H3PMo12O40 (H3PMo), H3PW12O40 (H3PW), and H5PMo10V2O40 (H5PMoV2) by density functional theory calculations and experiments shows that H3PMo is especially promising. Activation of O2 to •O2– and 1O2 via one-electron transfer assists the depolymerization process of cellulose by acidic/redox H3PMo. The reduced form [PMo10VIMo2VO39]5– plays a crucial role in GA production due to its high activity and ability to stabilize the intermediates of the retro-aldol reaction. H3PMo was furthermore complexed by the ionic liquid 1-(3-sulfonic group) propyl-3-methyl imidazolium (MIMPS), which enables easy recovery from the reaction solution due to temperature-responsive properties of the complexes. [MIMPS]H2PMo provides an outstanding GA selectivity of 61% under aerobic conditions and is comparable to the homogeneous H3PMo. Activity and selectivity to GA could be improved to 100 and 75%, respectively, by performing the reaction in the microwave at 190 °C for 2 min. The work deepens the insight on cellulosic biomass transformation over POMs by acidic/oxidative synergetic catalysis and contributes to the effort of designing highly active, selective, and multifunctional catalysts.

Full Utilization of Lignocellulose with Ionic Liquid Polyoxometalates in a One-Pot Three-Step Conversion.

The lignin-first concept is a new innovation for full utilization of lignocellulose into value-added chemicals. Ionic liquid (IL) polyoxometalates [MIMPS]2 H4 P2 Mo18 O62 [MIMPS=1-(3-sulfonic group) propyl-3-methyl imidazolium] are reported to be active in the cleavage of β-O-4, α-O-4, and 4-O-5 bonds in three kinds of lignin models and also efficient for converting native lignocellulose. The three components in soft or hard lignocellulose were depolymerized in a one-pot three-step treatment. For soft lignocellulose (pine), lignin was first decomposed into guaiacol and phenol with yields of 15.3 and 12.9 % at 98.6 % delignification efficiency at 130 °C for 14 h. Meanwhile, hemicellulose and cellulose were intact during the delignifying process and were subsequently hydrolyzed to 3.5 % xylose at 100 % hemicellulose conversion efficiency at 150 °C for 14 h and 36.4 % glucose at 100 % cellulose conversion efficiency at 170 °C for 12 h, respectively. For hard lignocellulose (poplar), the yields of guaiacol and phenol were 10.1 and 8.7 % at 91.9 % delignification efficiency at 130 °C for 14 h, whereas 12.9 % xylose at 90.4 % hemicellulose conversion efficiency at 150 °C for 12 h and 32.9 % glucose at 100 % cellulose conversion efficiency at 170 °C for 12 h were obtained. [MIMPS]2 H4 P2 Mo18 O62 achieved the full utilization of lignocellulose with total conversion in the lignin-first strategy and also showed the easy separation as a result of temperature-reversibility with ten recycling runs.

Synthesis and Characterization of a New Nano Ionic Liquid Based on Dawson-Type Polyoxometalate and Its Application in the Synthesis of Symmetrical N,N′-Alkylidene Bisamides

A new organic-inorganic nano hybrid ionic liquid based on polyoxometalate H2 [MIMBS]4 [P2W18O62]·11 H2O (MIMBS − P2W18), originated from self-assembling of Dawson-type polyoxometalate [P2W18 O62]6− and organic ionic liquid [1-(3-sulfonic group) butyl-3-methyl imidazolium (MIMBS)] components, has been successfully prepared and characterized by elemental analysis, Fourier transform infrared (FT-IR), 1H, 13C, and 15P nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The analysis results present that the size range of the nanosheets are between 40 and 50 nm. The resulting heterogeneous catalyst is shown to be an efficient acidic catalyst for the synthesis of symmetrical N, N′-alkylidene bisamides under solvent-free conditions at 80 °C in high yields. After completion of reaction, the catalyst was simply recovered by filtration and recycled without significant loss in the catalytic activity. The hallmark privileges presented by this method are green chemistry, mild condition, simple method and great yield.

A Novel Keggin-type Monovanadium-substituted Polyoxometalate-based Electrolyte

A novel Keggin-type polyoxometalate-based electrolyte, [TEAPS]4PW11VO40, has been synthesized by triethylamine containing 1-(3-sulfonic group) propyl (TEAPS) and monovanadium-substituted Keggin heteropoly acid (H4PW11VO40) and characterized by IR, UV, XRD, TG-DTA. The product is solid state with high viscosity at room temperature and it shows a phase transition as the temperature is raised. It exhibits high conductivity (3.90×10-3 S·cm-1 at 83 °C and 30% relative humidity), with a conductive activation energy of 23.78 kJ·mol-1. In the range of measured temperature, its conductivity increases with higher temperature.

Synthesis and Characterization of a Novel Polyoxometalate Gel Electrolyte

A novel polyoxometalate gel electrolyte was synthesized by 1-(3-sulfonic group) propyl-3-methyl imidazolium (abbreviated as MIMPS) and H5SiW11VO40. The synthesized gel electrolyte was successfully characterized by infrared spectra (IR), ultraviolet spectra(UV) and X-ray diffraction (XRD). Theresults of the characterization indicate that existence of Keggin structure heteropolyanion in the tungstovanadosilicate-based ionic liquid gel. The change from crystal to amorphous was observed in the XRD patterns, before and after the cation (MIMPS) added.

A polyoxometalate gel electrolyte with enhanced electrochemical performance

A novel hybrid gel electrolyte has been synthesized by self-assembling of 1-(3-sulfonic group) propyl pyridine (PyPS) cation and the heteropoly anion. The results of FTIR spectra and XRD patterns indicate the synthesized hybrid gel electrolyte [PyPS]5SiMo[Formula: see text]VO[Formula: see text] possesses lamellar structure with [Formula: see text]-spacing of 2.09[Formula: see text]nm. The electrochemical stability potential window is up to 3[Formula: see text]V. Ionic conductivity of [Formula: see text][Formula: see text]S[Formula: see text]cm[Formula: see text] was observed above the phase transformation temperature under ambient condition. The conductivity enhances with increasing temperatures.

Preparation and application of poly(zwitterionic ionic liquid) to enhance the photocatalytic activity of TiO2

A novel composite material PIL@TiO2 was synthesized by sol–gel method using zwitterionic ionic liquid (1-(3-sulfonic group) propyl-3-ethylimidazole). TiO2 was uniformly loaded on PIL (poly(1-(3-sulfonic group) propyl-3-ethylimidazole)). The large specific surface area, unique microspore structure, negative effect, and synergistic effect were caused by PIL. PIL@TiO2 can effectively improve the separation efficiency of the electron–hole photogeneration. The electron–hole pair and ·OH play an important role in the photo-degradation. The structure of dye molecule is also an influencing factor for the degradation capacity. After five cycle experiments, PIL@TiO2 still exhibited excellent photocatalytic efficiency to dye molecules and its photocatalytic efficiency is better than that of P-25 (nanoscale TiO2) in the methyl orange and Rhodamine B solutions.

Temperature-dependent gel-type ionic liquid compounds based on vanadium-substituted polyoxometalates with Keggin structure.

A series of temperature-dependent gel-type ionic liquid compounds have been synthesized from 1-(3-sulfonic group) propyl-3-methyl imidazolium (abbreviated as MIMPS) and three vanadium-substituted heteropoly acids H5SiW11VO40, H5SiMo11VO40 and H7SiW9V3O40. The designed and synthesized gel-type polyoxometalate ionic liquids (POM-ILs) have demonstrated a tendency to exhibit a layered structure. Moreover, they can undergo a phase transformation from a viscous gel-state to a liquid-state below 100 °C, and ionic conductivity up to 10(-3) S cm(-1) was observed at 120 °C. Cyclic voltammetry was carried out to study their electrochemical properties in organic solutions, and it was found that the oxidizability of the three POM-ILs decreases in the order: [MIMPS]7SiW9V3O40 > [MIMPS]5SiMo11VO40 > [MIMPS]5SiW11VO40. This result indicates that the redox behavior can be tuned by changing the chemical composition of the heteropolyanions.

Reversible phase transformation gel-type ionic liquid compounds based on tungstovanadosilicates

A series of new reversible phase transformation gel-type ionic liquid compounds, [PyPS]5SiW11VO40, [PyPS]7SiW9V3O40, [TEAPS]5SiW11VO40 and [TEAPS]7SiW9V3O40, have been synthesized from two organic ammoniums 1-(3-sulfonic group) propyl-pyridine (PyPS), 1-(3-sulfonic group) propyl-triethylammonium (TEAPS) and vanadium-substituted heteropoly acids H5SiW11VO40 and H7SiW9V3O40. The products can undergo a phase transformation from viscous gel-state to liquid-state below 100 °C, and ionic conductivity up to 10−3 S cm−1 was observed at 110 °C for these gel-type POM-ILs. The relationship between the component elements of the products and their physicochemical property has been studied. Their thermostability was measured using thermogravimetric and differential thermal analysis (TG-DTA), and the result indicates that the less vanadium atoms there are inside the heteropoly anion, the more stable the POM-IL is at high temperature. Cyclic voltammetry is carried out to study their electrochemical properties in organic solution. The potential values of redox waves confirm that the oxidability of these gel-type POM-ILs can be controlled upon changing the number of vanadium atoms in the heteropolyanions.

Hybrid Gel Electrolytes Derived from Keggin-Type Polyoxometalates and Imidazolium-Based Ionic Liquid with Enhanced Electrochemical Stability and Fast Ionic Conductivity

New hybrid gel electrolytes, derived from synergetic self-assembling of inorganic polyoxometalates (POMs) and organic ionic liquid (IL) components, have been successfully prepared using Keggin-type heteropolyanions such as {PMo11VO40}4– and {PW11MoO40}3– and ionic liquid N-methyl imidazolium-1-(3-sulfonic group) propyl (MIMPS). Powder X-ray diffraction study reveals that these hybrid gels possess lamellar structure and exhibit characteristic thermo-tropic liquid-crystalline behavior. Ionic conductivity (σ) of ∼0.1 S cm–1 under ambient conduction was observed at 93 °C for [MIMPS]4PMo11VO40 (IL-PMo11V) and [MIMPS]3PW11MoO40 (IL-PW11Mo) hybrid gels. The electrochemical stability window (ESW) of IL-PMo11V and IL-PW11Mo seem to be about 2 and 4 V, respectively, at room temperature. The POM-based IL gel electrolytes show super ionic conductivity and high ESW compared to other known IL-based electrolytes, including 1-dodecyl-3-methylimidazolium-bis(pentafluoro-ethylsolfonyl)imide (σ = 0.003 S cm–1 at 94 °C, ESW = 3.5 V), 1-dodecylimidazolium-bis(pentafluoro-ethylsolfonyl)imide (σ = 0.002 S cm–1 at 94 °C, ESW = 3 V), SiO2/1-methy-3-propylpiperidinium/bis(trifluoro methanesulphonyl)imide (σ = 0.014 S cm–1 at 85 °C, ESW = 1.5 V), and 1-ethyl-3-methylimidazolium tetracyanoborate/poly(vinylidene fluride-co-hexafluoropropylene (σ = 0.027 S cm–1 at 90 °C, ESW = 3.8 V).

ChemInform Abstract: Effects of Different Reaction Conditions on the Synthesis of Terpinyl Acetate.

The main properties of terpinyl acetate have been introduced. Different catalysts that consist of solid superacid SO4 2- /ZnO-TiO2, SnCl4 · 5 H2 O, H3PO4/[C4 mim]BF4, functional polyether ionic liquid (1-(3-sulfonic group)propyl -3 -polyoxyethyleneimi - dazole dihydrogen phosphate ([HS03 - (CH2)3 - im- (CH2CH2O)nH]H2PO4)) and SO2- 4 /SnO2 -CeO2 have also been introduced. Effects of different reaction conditions such as the amount of catalyst, the molar ratio of terpineol to acetic anhydridel, the reaction temperature, the reaction time and reusable catalyst times are discussed. The optimum amount of catalyst, the molar ratio of terpineol to acetic anhydridel, the reaction temperature, the reaction time and reusable catalyst times are beneficial to improve the yield of terpinyl acetate.

Reversible phase transformation-type electrolyte based on layered shape polyoxometalate

Reversible phase transformation-type electrolyte, consisting of 1-(3-sulfonic group)propyl-3-methyl imidazolium cation (MIMPS) and tungstovanadophosphoric anion with Keggin structure, [MIMPS]4PW11VO40, is synthesized and characterized using elemental analysis, IR, UV, XRD, and TG-DTA. This product is in quasi-solid-state, a novel type of ionic liquid, with a layered type of structure. This compound can process the phase transition from a crystal phase to an isotropic phase below 100 °C. Moreover, the DTA and conductivity–temperature plot shows an observable increase in conductivity above 84.2 °C, which is caused by the phase transformation from crystal phase to isotropic phase. This novel electrolyte material exhibits high conductivity (8.60 × 10−2 S cm−1 at 83 °C and 80% relative humidity). In the range of the measured temperature, its conductivity increases with higher temperature, indicating that the conductive activation energy for this conduction step is 42.06 kJ mol−1.

Syntheses and electrochemical properties of polyoxometalate salts with Dawson structure

Two new solid hybrid molecular materials [PyPS]H6P2W17VO62 and [PyPS]H8P2W15V3O62 have been synthesized from 1-(3-sulfonic group) propyl-pyridine ionic liquid cation and tungstovanadophosphoric anion with the Dawson structure. They were characterized by element analysis, impedance spectroscopy (IS), IR- and UV-spectroscopy. The formation of the hybrid molecular compounds with the Dawson structure was showed. Ion conductivity of [PyPS]H6P2W17VO62 and [PyPS]H8P2W15V3O62 are 3.99 × 10−3 and 7.37 × 10−3 S cm−1 at 18°C and 55% relative humidity respectively. The activation energies of proton conductivity are 28.2 and 26.7 kJ mol−1 respectively.

Synthesis and conductivity of hybrid materials based on germanium-containing polyoxometalates and ionic liquids

Three new compounds, [MIMPS]5GeW11VO40, [MIMPS]5GeW10MoVO40, and [MIMPS]5GeMo11VO40, have been synthesized from 1-(3-sulfonic group) propyl-3-methyl imidazolium (MIMPS, C7H13N2O3) and germanium-containing heteropoly acids H5GeW11VO40, H5GeW10MoVO40, and H5GeMo11VO40. IR spectra indicate the formation of the hybrid molecular compounds showing fingerprint vibrational bands of both heteropolyanions and MIMPS cations. The products exhibit high conductivity and small conductive activation energies; conductivities increase with higher temperature. Their conductivities are as follows: [MIMPS]5GeW11VO40 > [MIMPS]5GeW10MoVO40 > [MIMPS]5GeMo11VO40. The sequence is opposite for their conductive activation energies. The results show that the conductivity and conductive activation energies are closely related to their component elements. The W-containing material exhibits higher conductivity and smaller conductive activation energy than Mo-containing material.

The Catalytic Performance Comparison of Two Different Pyrrolidone Type Ionic Liquid in Biodiesel Production from Soybean Oil

Two different ionic liquid of the N-(3-sulfonic group) propyl pyrrolidone hydrosulfate ([C3SO3Hnhp]HSO4) and the 2-pyrrolidone hydrosulfate ([Hnhp]HSO4) have been synthesized and used as catalyst for the biodiesel production from the soybean oil. The former exhibited better catalytic performance than that of the later one and the reaction conditions corresponding to [C3SO3Hnhp]HSO4 were optimized. Under the optimal condition the yield of methyl ester reached 93.6% and after repeatedly used for four times the catalytic activity for [C3SO3Hnhp]HSO4 still maintained in a high level.

Polyoxometalate-based ionic liquids as catalysts for deep desulfurization of fuels

In order to obtain the ultra low-sulfur diesel, deep desulfurization of diesel oil has become a vital subject of environmental catalysis studies. Extraction and catalytic oxidation desulfurization (ECODS) system is one of the most promising desulfurization processes. A series of Keggin-type POM-based ionic liquids hybrid materials [MIMPS] 3PW 12O 40·2H 2O (1-(3-sulfonic group) propyl-3-methyl imidazolium phosphotungstate), [Bmim] 3PW 12O 40 (1-butyl 3-methyl imidazolium phosphotungstate), [Bmim] 3PMo 12O 40 (1-butyl 3-methyl imidazolium phosphomolybdate) and [Bmim] 4SiW 12O 40 (1-butyl-3-methyl imidazolium silicotungstate) have been developed in this study, and the reaction has performed using the POM-ILs materials as catalysts, H 2O 2 as oxidant, and ionic liquid (IL) as solvent. Through experimental evaluations, [MIMPS] 3PW 12O 40·2H 2O was found to be the best catalyst, with an S-removal of 100% at 30 °C for 1 h. The main factors affecting the process including temperature, catalyst dosage, and O/S (H 2O 2/DBT) molar ratio were investigated in detail. Under the optimal conditions, DBT (dibenzothiophene) and 4,6-DMDBT (4,6-dimethyl-dibenzothiophene) could achieve high desulfurization efficiency. Moreover, the reaction system also exhibited high activity in actual diesel oil, which could be reduced from 1113 ppm to 198 ppm. The reaction system could recycle 8-times with a slight decrease in activity.