Ionic liquid dissolution utilized for biomass conversion into biofuels, value-added chemicals and advanced materials: A comprehensive review

Industrial waste gas is one of the major sources of atmospheric CO2, yet the direct conversion of the low concentrations of CO2 in waste gases into high value-added chemicals have been a great challenge. Herein, a copper-based N-heterocyclic carbene porous polymer catalyst (Cu@NHC-1) for the direct conversion of low concentration CO2 into oxazolidinones was successfully fabricated via a facile copolymerization process followed by the complexation with Cu(OAc)2. A continuous flow device was designed to deliver a continuous and stable carbon source for the reaction. Due to the triply synergistic effect of its porous structure, nitrogen activation sites and catalytic Cu center, Cu@NHC-1 shows highly efficient and selective adsorption, activation, and conversion of the low concentration CO2 (30 vol.%). Its practical application potential is demonstrated by the ability to successfully convert the CO2 in lime kiln waste gas into oxazolidinones in satisfactory yields under mild conditions.

Direct Conversion of CO 2  in Lime Kiln Waste Gas Catalyzed by a Copper-Based N -heterocyclic Carbene Porous Polymer.

Supported ionic liquid-copper catalyst for synergistically catalytic and highly efficient hydration of acetylene

Abstract C18H20F12N4P2, monoclinic, P21/n (no. 14), a = 8.3185(9) Å, b = 21.883(2) Å, c = 13.4345(15) Å, β = 103.4730(10)°, V = 2378.3(5) Å3, Z = 4, Rgt(F) = 0.0470, wRref(F2) = 0.1305, T = 296(2) K.

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Crystal structure of 3,3′-(1,2-phenylene-bis(methylene))bis(1-vinyl- 1H-imidazol-3-ium) bis(hexafluoro phosphate)(V), C18H20F12N4P2

<jats:p>[C<jats:sub>9</jats:sub>H<jats:sub>13</jats:sub>F<jats:sub>6</jats:sub>N<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>P], monoclinic, <jats:italic>P</jats:italic>2<jats:sub>1</jats:sub>/<jats:italic>c</jats:italic> (no. 14), <jats:italic>a</jats:italic> = 6.5994(13) Å, <jats:italic>b</jats:italic> = 10.754(2) Å, <jats:italic>c</jats:italic> = 19.754(4) Å, <jats:italic>β</jats:italic> = 96.267(2)°, <jats:italic>V</jats:italic> = 1393.6(5) Å<jats:sup>3</jats:sup>, <jats:italic>Z</jats:italic> = 4, <jats:italic>R</jats:italic><jats:sub>gt</jats:sub>(<jats:italic>F</jats:italic>) = 0.0674, <jats:italic>wR</jats:italic><jats:sub>ref</jats:sub>(<jats:italic>F</jats:italic><jats:sup>2</jats:sup>) = 0.2124, <jats:italic>T</jats:italic> = 296(2) K.</jats:p>

Crystal structure of 3-(2-ethoxy-2-oxoethyl)-1-vinyl-1H-imidazol-3-ium hexafluoridophosphate(V), C9H13F6N2O2P

Synthesis and characterization of diimidazole-based hexafluorophosphate ionic liquids

Crystal structure of methyl 4-acetoxy-3,5-dimethoxybenzoate, C12H14O6

In this work, functionalized alkyl imidazolium hexafluorophosphate ILs were synthesized and characterized, and then they were applied in the conversion of xylose to furfural under the microwave. The results showed that when CnMF was used as a catalyst, an acidic environment was provided to promote the formation of furfural. In addition, not only the heating method and the solvent, but also the different structurally of cations in the ionic liquid had an influence on their catalytic activity. In aqueous solution, the yield of furfural obtained under microwave was better than conventional heating method, and the catalytic activity of diimidazole hexafluorophosphate was better than that of monoimidazole. Meanwhile, for the diimidazole hexafluorophosphate, the change of the carbon chain length between the imidazole rings also had a slight influence on the yield. Finally, the optimal yield of 49.76% was obtained at 205℃ for 8 minutes using (3,3'-methylenebis(1-methyl-1H-imidazol-3-ium), C1MF) as catalyst. Mechanistic studies suggested that the catalytic activity of C1MF was mainly due to the combined effect of POFn (OH)3-n and imidazole ring. Without a doubt, the catalytic activity of C1MF was still available after five cycles, which not only showed its excellent catalytic activity in catalyzing the xylose to prepare the biomass platform compound furfural, but also could promote the application of functionalized ionic liquids.

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Preparation of Furfural From Xylose Catalyzed by Diimidazole Hexafluorophosphate in Microwave.

Abstract C11H18F12N4P2, monoclinic, P21/c (no. 14), a = 14.975(3) Å, b = 9.897(2) Å, c = 13.525(3) Å, β = 105.507(3)°, V = 1931.5(7) Å3, Z = 4, Rgt(F) = 0.0590, wRref(F2) = 0.1843, T = 296(2) K.

/pdf/crystal-structure-of-1-1-methylenebis-3-ethyl-1h-imidazol-3-12ej52tb0x.pdf

Wan-Ming Xiong

Papers

Synthesis and characterization of diimidazole-based hexafluorophosphate ionic liquids

Crystal structure of methyl 4-acetoxy-3,5-dimethoxybenzoate, C12H14O6

Preparation of Furfural From Xylose Catalyzed by Diimidazole Hexafluorophosphate in Microwave.

Crystal structure of 3-(2-ethoxy-2-oxoethyl)-1-vinyl-1H-imidazol-3-ium hexafluoridophosphate(V), C9H13F6N2O2P

Crystal structure of 1,1′-methylenebis(3-ethyl-1H-imidazol-3-ium) bis(hexafluorophosphate(V)), C11H18F12N4P2