科创中国

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 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.

Shaojuan Zeng;Hongyan He;Hongshuai Gao;香平 张;Jian Wang;Ying Huang;锁江 张

RSC Advances

2015

BACKGROUND: Aqueous solutions of amine are considered to be effective absorbents for CO₂ capture. Special attention is increasingly being given to developing efficient solvents with both high absorption rate and absorption loading for CO₂ capture. RESULTS: A novel amine 2-[(3-aminopropyl)methylamino]ethanol (HMPDA) containing a primary amino group and a tertiary amino group was screened to improve the CO₂ absorption performance. The equilibrium loading of CO₂ in aqueous HMPDA solution was found to be 1.65mol CO₂ mol^-1 HMPDA at 313K and 1 MPa, which is larger than those of conventional amines like monoethanolamine (MEA, 0.75mol CO₂ mol^-1 MEA) and N-methyldiethanolamine (MDEA, 1.05mol CO₂ mol^-1 MDEA) at 313K and 1 MPa. Moreover, the HMPDA solution demonstrated a faster absorption rate of CO₂ than those of MEA and MDEA solutions. The viscosity of HMPDA solution increases by around 66% after CO₂ absorption, which is smaller than the 88% increase of MEA solution. CONCLUSIONS: Efficient results for CO₂ absorption using HMPDA were obtained through assessing the absorption rate, absorption loading of CO₂ and related physical properties. This novel amine shows both fast absorption rate and high absorption loading due to the multiple-site reaction elaborated by the zwitterion and single-step termolecular mechanism.

Lingdi Cao;Haifeng Dong;香平 张;锁江 张;Zhijun Zhao;Shaojuan Zeng;Jubao Gao

Journal of Chemical Technology and Biotechnology

2015-10-1

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.

Guohui Zhou;Xiaomin Liu;锁江 张;光认 于;Hongyan He

Journal of Physical Chemistry B

2007-6-28

In hypergolic propellants, hypergolicity is an extremely important parameter in evaluating fuels. In this study, a new family of hypergolic metal (Cu²⁺, Ni²⁺, Zn²⁺) complexes with B₁₂H₁₂ ^2– were synthesized and fully characterized. Two of these six complexes exhibited ultrashort ignition delay times (ca. 1 ms), with white fuming nitric acid as the oxidizer, besides good physicochemical properties (decomposition temperatures: 221.8–286.3 °C; densities: 1.215–1.264 g cm^–3). The results demonstrate their promising applications in bipropellant formulations.

Zejun Zhang;Yanqiang Zhang;Zhimin Li;Nianming Jiao;Long Liu;锁江 张

European Journal of Inorganic Chemistry

2018-2-28

A series of novel heteropoly catalysts (H₄PMo₁₁VO₄₀/Cs₄PMo₁₁VO₄₀) with core shell structure were designed and synthesized for effective oxidation of methacrolein to methacrylic acid. The effects of H₄PMo₁₁VO₄₀ supporting amount on catalytic properties were investigated. With the hydrothermal treatment temperature increased from 25 to 180 °C, the surface area of Cs₄PMo₁₁VO₄₀ decreased from 123.6 to 7.7 m² g⁻¹, while the acidity and oxidation susceptibility of Cs₄PMo₁₁VO₄₀ were enhanced due to its re-crystallization. The XRD results showed that the crystalline form of H₄PMo₁₁VO₄₀ changed from triclinic to cubic form because of the guidance effect of Cs₄PMo₁₁VO₄₀. BET, NH₃-TPD and XPS results indicated that compared with bulk H₄PMo₁₁VO₄₀, surface area and oxidation susceptibility of the supported one increased significantly, and the acidity decreased. The sui thickness of H₄PMo₁₁VO₄₀ layer on Cs₄PMo₁₁VO₄₀ was a key point to tune the surface area, oxidation susceptibility and acidity of catalysts. At 310 °C, the methacrolein conversion and methacrylic acid selectivity on the optimum supported catalyst were more than 85% and 75%, respectively, which were much better than those on bulk H₄PMo₁₁VO₄₀ (39% and 46%), Cs₄PMo₁₁VO₄₀ (15.6% and 0%) and Cs_2.6H_1.4PMo₁₁VO₄₀ (99.9% and 36.5%).

Lilong Zhou;Lei Wang;Yanyan Diao;Ruiyi Yan;锁江 张

Molecular Catalysis

2017

Molecular dynamics simulations were performed based on the all-atom (AA) force fields for three kinds of acyclic guanidinium-based ionic liquids (ILs), which composed by dimethyldihexylguanidinium cation and three different types of anions. The force field parameters were developed based on our previous work for guanidinium-based ILs [X. Liu, S. Zhang, G. Zhou, G. Wu, X. Yuan, X. Yao, J. Phys. Chem. B 110 (2006) 12062-12071; X. Liu, G. Zhou, S. Zhang, G. Wu, G. Yu, J. Phys. Chem. B 111 (2007) 5658-5668]. Validation was carried out by comparing simulation densities with experimental data, and they are in good agreement. Dynamics properties including the coefficient of self-diffusions, viscosities and molar conductivities for these ILs were predicted. To depict the microscopic structures of the ILs, both spatial distribution functions and radial distribution functions were investigated.

Xiaomin Liu;Guohui Zhou;锁江 张

Fluid Phase Equilibria

2008-10-25

A mild oxidative esterification of various aromatic aldehydes by sulfate radical redox system was presented. In the reaction pathway exploration, the transiency of MeOSO₃^- was disclosed, which was generated from esterification between the in situ generated HSO₄^- and MeOH, a rate-limiting step in the process. More importantly, the selectivity-controlling step was represented by the subsequent nucleophilic displacement between MeOSO₃^- and aldehydes. The ionic oxidant 1a ((NH₄)₂S₂O₈) with more N-H numbers in the cation, as compared with 1c ((n-Bu₄N)₂S₂O₈) and 1d ((PyH)₂S₂O₈), has better performance in the oxidative esterification of aldehydes.

Ya Fei Guo;Sajid Mahmood;Bao Hua Xu;Xiao Qian Yao;Hong Yan He;锁江 张

Journal of Organic Chemistry

2017-2-3

Ionic liquid (IL)-amine hybrid solvents have been experimentally proved to be effective for CO₂ capture. This Article provided rigorous thermodynamic models, process simulation, and cost estimation of a potential design of IL-based CO₂ capture processes. Three ILs ([Bmim][BF ₄], [Bmim][DCA], and [Bpy][BF₄]) were investigated to blend with MEA aqueous solution. The physicochemical properties of the ILs were predicted by several temperature-dependent correlations. Phase equilibria were modeled based on Henrys law and NRTL equation, and the calculated values were in good agreement with the experimental data. The simulation results show that the [Bpy][BF₄]-MEA process can save about 15% regeneration heat duty as compared to the conventional MEA process, which is attributed to the reduction of sensible and latent heat. Moreover, a modified [Bpy][BF₄]-MEA process via adding intercooling and lean vapor recompression presents 12% and 13.5% reduction in overall equivalent energy penalty and capture cost as compared to the conventional MEA process, respectively.

Ying Huang;香平 张;Xin Zhang;Haifeng Dong;锁江 张

Industrial & Engineering Chemistry Research

2014-7-23

T-Nb₂O₅/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb₂O₅ nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb₂O₅ nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb₂O₅ nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g⁻¹. Additionally, non-aqueous asymmetric supercapacitors (ASCs) were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF₆-based organic electrolyte achieved an energy density of 45.1 Wh·kg⁻¹ at 715.2 W·kg⁻¹. The working potential could be further enhanced to 4 V when a polymer ionogel separator (PVDF-HFP/LiTFSI/EMIMBF₄) and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60 °C and delivered a maximum energy density of 70 Wh·kg⁻¹ at 1 kW·kg⁻¹.

Yuzhi Jiao;Haitao Zhang;Hailang Zhang;Ao Liu;Yanxia Liu;锁江 张

Nano Research

2018-9-1

[Bis(imidazolyl)–BH₂]⁺[bis(triazolyl)–BH₂]⁻ and [bis(imidazolyl)–BH₂]⁺[tris(triazolyl)–BH]⁻ were synthesized, the cations and anions of which were functionalized with B−H groups and azoles. As B−H groups contribute to the hypergolic activity and azole groups improve the energy output, the resulting ionic liquids exhibited ignition delay times as low as 20 ms and energy outputs as high as 461.1 kJ mol⁻¹. In addition, densities (1.07–1.22 g cm⁻³) and density-specific impulse (≈360 s g cm⁻³) values reached a relatively high level. These ionic liquids show great promise as sustainable rocket fuels.

Nianming Jiao;Yanqiang Zhang;Hao Li;Long Liu;锁江 张

Chemistry - An Asian Journal

2018-8-6