王兰云, 周华健, 张亚娟.CO₂在｛［Bmim］［BF4］+碱金属盐｝金属络合离子液体中的溶解度及溶解机理研究[J].河南理工大学学报（自然科学版）,2023,42(6):86-95.

WANG L Y, ZHOU H J, ZHANG Y J.On the solubility and dissolution mechanism of CO₂ in ｛［Bmim］［BF4］⁺ alkali metal salt｝ metal complex ionic liquid[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(6):86-95.

CO₂在｛［Bmim］［BF4］+碱金属盐｝金属络合离子液体中的溶解度及溶解机理研究

王兰云1,2,3, 周华健1, 张亚娟1

1.河南理工大学 安全科学与工程学院，河南 焦作  454000;2.河南理工大学 瓦斯地质与瓦斯控制国家重点实验室培育基地，河南 焦作  454000;3.河南理工大学 煤炭安全生产与清洁高效利用省部共建协同创新中心，河南 焦作  454000

摘要:为更加经济有效地捕获CO2，减少环境污染，加强资源合理利用，制备不同浓度的［Bmim］［BF₄］+MBF₄（M=Li⁺，Na⁺和K⁺）金属络合离子液体，在压力100～4 000 kPa，温度30，40，50 ℃条件下，使用反应釜进行气体吸收试验，测定CO₂在金属络合离子液体（metal complex ionic liquids，MILs）中的溶解度，并采用密度泛函模拟计算MILs与CO₂混合体系的稳定构型的电荷分布、Fukui指数和结合能参数，从微观角度分析MILs吸收CO₂机理。结果表明：CO₂在MILs中的溶解度随温度升高和压力降低而降低；添加碱金属盐可促进离子液体（ionic liquids，ILs）对CO₂的吸收，但当ILs中碱金属盐浓度≥1 mol/L时会抑制CO₂吸收；0.010 mol/L的［Bmim］［BF₄］+KBF₄吸收CO₂量最高；密度泛函计算结果显示［Bmim］［BF₄］+KBF₄体系的K⁺体积大，氢键作用力强，且K⁺在ILs中溶解度小，造成的空间位阻较小，因而拥有更多的自由体积容纳CO₂。与纯ILs相比，MILs具有更高的CO₂吸收量，在温室气体治理中具有较好的应用前景。

关键词: CO₂吸收;碱金属盐;［Bmim］［BF₄］离子液体;金属络合离子液体;密度泛函计算

doi:10.16186/j.cnki.1673-9787.2021100022

基金项目:国家自然科学基金资助项目（51874124，52074108）；河南省科技攻关项目（212102310007）；河南省高校重点科研项目（22A620001）；河南省高校创新人才项目（22HASTIT012）

收稿日期:2021/10/12

修回日期:2021/12/20

出版日期:2023/11/25

On the solubility and dissolution mechanism of CO2 in ｛［Bmim］［BF4］+alkali metal salt｝ metal complex ionic liquid

WANG Lanyun1,2,3, ZHOU Huajian1, ZHANG Yajuan1

1.School of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.Cultivation Base of State Key Laboratory of Gas Geology and Gas Control，Henan Polytechnic University，Jiaozuo  454000，Henan，China;3.Co-construction and Cooperation Between the Provinces and Departments for Safe Production and Clean and Efficient Utilization of Coal Innovation Center，Henan Polytechnic University，Jiaozuo  454000，Henan，China

Abstract:In order to capture carbon dioxide more economically and effectively，reduce environmental pollution，and strengthen the rational use of resources，various concentrations of metal complex ionic liquids ［Bmim］［BF₄］+MBF₄（M=Li⁺，Na⁺ and K⁺）were prepared in this paper.Under the pressure range of 100～4 000 kPa，the gas absorption experiment was carried out at 30，40 and 50 ℃ by using a high-pressure reactor，and the solubility of CO₂ in metal complex ionic liquids（MILs） was measured.Density functional simulation was used to calculate the charge distribution，Fukui index，and binding energy parameters of the stable configuration of the mixed system of MILs and CO₂，and to analyze the CO₂ absorption mechanism of MILs from a microscopic perspective.The experimental results show that the solubility of CO₂ in MILs decreases with increasing temperature and decreasing pressure.Adding alkali metal salt can promote the absorption of CO₂ by ILs，but when the concentration of alkali metal salt in ILs is ≥1 mol/L，it will inhibit CO₂ absorption.Besides，0.010 mol/L ［Bmim］［BF₄］+KBF₄ absorbs the highest amount of CO₂.The density functional calculation results demonstrate that ［Bmim］［BF₄］+KBF₄ has a large K⁺ volume and strong hydrogen bond force，and the solubility of K⁺ in the ionic liquid is small，resulting in less steric hindrance，so ［Bmim］［BF₄］+KBF₄ has more free volume to accommodate CO₂.Overall，MILs have higher CO₂ absorption than pure ILs，and have a better application prospects in  greenhouse gases management.

Key words:CO₂ absorption;alkali metal salts;［Bmim］［BF₄］ ionic liquid;metal complex ionic liquid;density functional

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