Hongyan He

Northeast Institute of Geography and Agroecology, Beijing, Beijing Shi, China

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Publications (6)9.81 Total impact

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    ABSTRACT: In this work, three kinds of novel functionalized ionic liquids (ILs) [NEt2C2Py][SCN], [C4OPy][SCN] and [C4CNPy][SCN] were developed by introducing a tertiary amino group, ether group and nitrile group on the pyridinium cation to improve SO2 absorption performances. Among the investigated ILs, [NEt2C2Py][SCN] showed the highest absorption capacity of 1.06 gSO2•gIL-1 under ambient conditions due to a combination of the chemical and physical absorption. By contrast, the enhancement in SO2 capacity by [C4CNPy][SCN] and [C4OPy][SCN] is mainly ascribed to the stronger physical interaction between ILs and SO2 than the conventional IL [C4Py][SCN]. Meanwhile, higher SO2/CO2 selectivity was also obtained using these functionalized ILs, which was increased up to 41% comparing with that of [C4Py][SCN]. Moreover, the effect of water on SO2 capacity and the absorption mechanism were studied. The results indicated that the presence of water caused a slight decrease in SO2 capacity of [C4CNPy][SCN] and [C4OPy][SCN] because of physical absorption, whereas a slight increase in SO2 capacity by [NEt2C2Py][SCN] due to the formation of hydrogen sulfite salts through chemical absorption. In addition, three kinds of cation-functionalized ILs could remain the stable absorption performance after five cycles of absorption and desorption, implying these ILs show great potentials for SO2 capture.
    RSC Advances 12/2014; · 3.71 Impact Factor
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    ABSTRACT: The FeCl3-containing Lewis-acidic ionic liquids (ILs) [C6mim]Cl/FeCl3(1:1.5), [C6mim]Cl/FeCl3(1:2), [C8mim]Cl/FeCl3(1:1.5), and [C8mim]Cl/FeCl3(1:2) were used as extractants for desulfurization of model fuel and gasoline fuel, respectively. The results demonstrate that these ILs are effective for the removal of sulfur compounds from model fuel under different mass ratio of IL to model fuel (1:1, 1:3, 1:5, 1:10) at 25°C. The extractive performance of ILs increased as the molar ratio of FeCl3 to [Cnmim]Cl(n = 6, 8) varied from 1:1 to 1:2. The selectivity of sulfur compounds by extraction process followed the order of dibenzothiophene (DBT)>benzothiophene (BT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT). The sulfur removal of gasoline fuel containing sulfur content of 440.3 ppmw could be up to 85.8%; that is to say that the sulfur content of gasoline fuel varied from 440.3 ppmw to 62.4 ppmw after one extraction stage. Moreover, the [C6mim]Cl/FeCl3(1:2) can be recycled for at least 4 times with a little decrease in the desulfurization activity.
    Separation Science and Technology 05/2014; 49(8). · 1.16 Impact Factor
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    ABSTRACT: The mechanism of cycloaddition reaction between carbon dioxide and epoxide, catalyzed by HEMIMC (1-(2-hydroxyl-ethyl)-3-methylimidazolium chloride), was investigated using the DFT (density functional theory) method. In the presence of HEMIMC, the reaction mechanism changed from single-step to multipath. Seven reaction pathways are reported here, including two steps, epoxide ring-opening and ring-closure of cyclic carbonate, or three main steps, epoxide ring-opening, carbon dioxide insertion, and ring-closure of cyclic carbonate. The catalytic activity of HEMIMC was studied, and the catalytic mechanism was elucidated. The nucleophilic attack of anion and hydrogen bond are two of the most important factors to promote the cycloaddition reaction, especially the OH functional group in HEMIMC. Finally, the influence of different anions on the catalytic activity was investigated.
    Industrial & Engineering Chemistry Research. 05/2014; 53(20):8426–8435.
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    ABSTRACT: The design and synthesis of biodegradable ionic liquids has been one of the ways to accelerate the pace of ionic liquid large-scale industrial applications and prevent environmental hazards. The knowledge of thermodynamic properties for the mixtures of biodegradable ionic liquids with organic solvent or water has been paramount for the design of many technological processes. In this work, the densities of two binary systems for biodegradable naphthenic acid ionic liquids, choline cyclohexane carboxylate ([Ch][CHC]), and choline cyclopentane carboxylate ([Ch][CPC]) with ethanol were measured over the whole range of compositions from (293.15 to 323.15) K. The excess molar volumes of two systems were obtained from experimental data and fitted to the Redlich−Kister equation. The results showed that VE values were negative over the entire composition range, and its absolute values increased slightly with increasing temperature from (293.15 to 323.15) K. A minimum value of the two systems was located at 0.3 and 0.4, respectively. Estimated coefficients and standard error value were also presented.
    Journal of Chemical and Engineering Data - J CHEM ENG DATA. 10/2009; 55(3).
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    ABSTRACT: An all-atom force field was set up for a new class of ionic liquids (ILs), tetrabutylphosphonium amino acid, on the basis of the AMBER force field with determining parameters related to the phosphorus atom and modifying several parameters. Ab initio quantum chemical calculations were employed to obtain molecular geometries, infrared frequencies, and torsion energy profiles. Atom partial charges were obtained by using the one-conformation, two-step restraint electrostatic potential approach. Molecular dynamics simulation was carried out in the isothermal-isobaric ensemble for 14 tetrabutylphosphonium amino acid ILs at two temperatures to validate the force field against the experimental densities and heat capacities at constant pressure. Computed thermodynamic properties are in good agreement with available experimental values. Moreover, radial distribution functions were investigated to depict the microscopic structures of these ILs.
    The Journal of Physical Chemistry B 07/2007; 111(25):7078-84. · 3.61 Impact Factor
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    ABSTRACT: Quantum chemical calculations of the structures and cation-anion interaction of 1-ethyl-3-methylimidazolium lactate ([Emim][ LAC]) ion pair at the B3LYP/6-31++G** theoretical level were performed. The relevant geometrical characteristics, energy properties, intermolecular H-bonds (H-bonds), and calculated IR vibrations with respect to isolated ions were systematically discussed. The natural bond orbital (NBO) and atoms in molecule (AIM) analyses were also employed to understand the nature of the interactions between cation and anion. The five most stable geometries were verified by analyzing the relative energies and interaction energies. It was found that the most of the C-H…O intermolecular H-bonds interactions in five stable conformers have some covalent character in nature. The elongation and red shift in IR spectrum of C-H bonds which involve in H-bonds is proved by electron transfers from the lone pairs of the carbonyl O atom of [LAC]− to the C-H antibonding orbital of the [Emim]+. The interaction modes are more favorable when the carbonyl O atoms of [LAC]− interact with the C2-H of the imidazolium ring and the C-H of the ethyl group through the formation of triple H-bonds.
    Science China-Chemistry 55(8). · 1.33 Impact Factor