离子液体捕集CO2

CO₂是导致温室效应的最主要成分,因此碳捕集技术的研究受到学术界和产业界的高度重视。离子液体具有不挥发、不燃烧、热稳定性好、溶解能力强、结构和性质可调节并可循环使用等特性,在CO₂的吸收/分离领域展现了广阔的应用前景。本文系统地综述了近年来常规离子液体、功能化离子液体、支撑离子液体膜、聚合离子液体以及离子液体与分子溶剂的混合物在捕集CO₂方面的研究进展;讨论了离子液体的阳离子结构、阴离子类型、烷基链长度、阴/阳离子的氟化程度和功能化、离子液体的负载作用和聚合效应以及体系的温度和压力对CO₂选择性捕集性能的影响;分析了可能的捕集机理以及各种捕集方法的优点和缺点;提出了目前需要进一步研究的若干重要问题,并对其发展前景进行了展望。     

含胺功能基团离子液体吸收CO2的研究

分别采用传统的加热回流法和微波反应法合成溴化1-(2-胺乙基)-3-甲基咪唑([NH2e-mim]Br)功能离子液体,并对其进行CO2吸收实验.实验结果表明:与加热回流法相比,微波法极大地节省反应时间,且产率高达91.8%.通过吸收和解吸实验发现,在常压298 K的温度下,[NH2e-mim]Br 吸收CO2的物质的量...     

烷基磺酸阴离子无卤素离子液体的物理化学性质研究(英文)

通过一步法合成了基于1,3-二烷基咪唑阳离子和甲烷磺酸或对甲苯磺酸阴离子的无卤素离子液体,并对它们的物理化学性质如聚集行为、表面性质、热性质、密度、黏度、折光率和电化学性质等进行了详细研究.结果表明在甲烷磺酸阴离子基离子液体中观察到离子液体中普遍存在的离子簇行为;同等条件下[BEim]MS的荧光光谱强度较[BEim]TS弱;[C12Mim]MS展现出液晶行为;[TS]-基离子液体有着较高的折光率,大于1.51.     

离子液体介导CO2化学转化研究进展

The efficient utilization of carbon dioxide (CO₂) as a C1 feedstock is of great significance for green and sustainable development. Therefore, the efficient chemical conversion of CO₂ into value-added products has recently attracted a lot of research attention in recent years. The transformation of CO₂ generally requires high-energy substrates, specific catalysts, and harsh reaction conditions due to its high thermodynamic stability and kinetic inertness. Consequently, several efforts have been dedicated toward the development of high-performance catalysts and new reaction routes for CO₂ conversion over the last few decades. To date, many routes of convert CO₂ into value-added chemicals have been proposed, together with the development of heterogeneous and homogeneous catalysts. Among the advanced catalysts reported to date, ionic liquids (ILs) have been widely investigated and show great potential for the efficient, selective, and economical conversion of CO₂ into highly valuable products under mild conditions, even under ambient conditions. Some task-specific ILs have been designed with unique functional groups (e.g., —OH, —SO₃H, —NH₂, —COOH, and —C≡N), which can act as the solvent, absorbent, activating agent, catalyst, or cocatalyst to realize the transformation of CO₂ under metal-free and mild conditions. In addition, a variety of catalytic systems composed of ILs and metal catalysts have also been reported for the transformation of CO₂, in which the combination of the IL and metal catalyst is responsible for CO₂ conversion with high efficiency. In this review article, we summarize the recent advances in IL-mediated CO₂ transformation into chemicals prepared via C—O, C—N, C—S, C—H, and C—C bond forming processes. ILs that can chemically capture CO₂ with high capacity are first introduced, which can activate CO₂ via the formation of IL-based carbonates or carbamates, thus realizing the transformation of CO₂ under metal-free and mild conditions. Recent progress in IL-mediated CO₂ transformations to form carbonates and various kinds of N- and S-containing compounds (e.g., oxazolidinones, ureas, benzimidazolones, formamides, methylamines, benzothiazoles, and other chemicals) as well as CO₂ hydrogenation to give formic acid, methane, acetic acid, low-carbon alcohols, and hydrocarbons has been summarized in this review with a focus on the reaction routes, catalytic systems, and reaction mechanism. In these reactions, ILs can simultaneously activate the substrate via strong H-bonding in addition to activating CO₂, and the cooperative effects among the ionic and molecular species and metal catalysts accomplish the reactions of CO₂ with various kinds of substrates to afford a wide range of value-added chemicals. Finally, the shortcomings and perspectives of ILs are discussed. In short, IL-mediated CO₂ transformations provide green and effective routes for the synthesis of high-value chemicals, which may have great potential for a wide range of applications.     

非均相离子液体催化CO2环加成反应研究进展

二氧化碳（CO2）是一种来源丰富的C1资源,在温和条件下实现CO2的资源化利用是当前研究的热点之一。CO2环加成反应制备环状碳酸酯是CO2资源化利用的重要途径之一。环状碳酸酯是电池电解液的优良介质,可承受较恶劣的光、热及化学变化;同时也是聚氨酯、聚碳酸酯等精细化工中间体,广泛应用于医药、化工、纺织、印染等领域。非均相离子液体催化剂具有化学和热稳定性好、合成过程简单和可重复使用等优势。本文重点总结了近年来非均相离子液体催化剂在CO2和环氧化物环加成反应中的应用,并对非均相离子液体催化CO2环加成反应的发展进行展望。     

咪唑类离子液体混合物吸收CO2性能研究

结合常规离子液体和功能型离子液体在吸收CO₂方面的优势,将两类咪唑类离子液体进行混合,对其吸收CO₂的效果和再生性能进行了实验研究。结果表明,两类咪唑类离子液体混合后流动性明显改善,与CO₂接触气液传质顺畅;常规离子液体[bmim][BF₄]和[bmim][Tf₂N]与胺功能型离子液体[NH₂e-mim][BF₄]混合物较单一的离子液体吸收CO₂的量大,[bmim][CH₃CO₂]与[NH₂e-mim][BF₄]混合后较单一的[bmim][CH₃CO₂]吸收量有明显的减低;随着常规咪唑类离子液体阳离子碳链增长,混合离子液体吸收CO₂的效果变强;与胺乙基功能型离子液体混合吸收CO₂时,阴离子为[Tf₂N]的常规咪唑类离子液体要比阴离子为[BF₄]的吸收效果好;离子液体混合物吸收CO₂后经再生循环利用10次,混合物质量基本不变,循环使用后吸收CO₂性能为初始吸收性能的75%~85%。     

功能离子液体[NH2p-bim]BF4吸收CO2的密度泛函研究

用密度泛函理论对功能化离子液体[NH2p-bim]BF4吸收CO2的作用机制进行了理论研究。在RB3LYP/6-311 G**的计算水平对离子液体[NH2p-bim]BF4的结构以及CO2与该离子液体反应可能生成的产物进行了全优化,获得了优化结构的振动频率和热力学数据。计算结果表明,离子液体[NH2p-bim]BF4吸收CO2主要是通过离子液体的阳离子[NH2p-bim] 自偶解离的[NHp-bim]与CO2分子结合生成[O2C-NHp-bim],其结合能为238-260 kJ/mol。     

以季鏻盐离子液体为反应介质的绿色有机反应*

与铵盐类离子液体比较,季鏻盐离子液体具有挥发性更低,物理、化学性质更加稳定,兼具催化功能等优点。近年来,季鏻盐离子液体作为一种绿色反应介质日益受到重视,很多类型的有机反应在季鏻盐离子液体中得到应用,收到了很好的效果。本文主要以2000年以来的期刊文献报道为线索,对季鏻盐离子液体的制备方法以及以其作为反应介质的绿色有机反应进行了综述。这些反应主要包括Diels-Alder反应、Heck反应、Suzuki反应、Buchwald-Hartwig 反应、Friedel-Crafts反应、Kornblum 取代反应、Grignard反应、羰基化反应、氢甲酰化反应、转移氢化反应、酯化反应等多种类型。特别是对于一些涉及强碱性反应条件或亲电取代的反应类型,季鏻盐离子液体具有特殊的优势。     

表面活性剂修饰对MCM-41负载离子液体吸附CO2影响的研究

以表面活性剂修饰的MCM-41为载体,采用浸渍法制备了负载离子液体[NH2p-mim][PF6]的二氧化碳吸附剂,考察了表面活性剂对离子液体在MCM-41上分散的影响以及所导致的CO2吸附性能的变化.利用红外光谱(FT-IR),X-射线衍射(XRD),高分辨透射电子显微镜(HRTEM),热重分析(TG)技术对所合成的负载型离子液体吸附剂进行了表征研究,并与其吸附CO2的性能变化、离子液体与表面活性剂相互作用方式等因素进行了关联.结果表明:MCM-41负载离子液体后对CO2的吸附性能略有提高,而经表面活性剂修饰的MCM-41负载离子液体后,对CO2的吸附容量较载体本身提高了2.5倍.这一方面是因为表面活性剂胶束改善了MCM-41上离子液体的分散性,另一方面是表面活性剂胶束对离子液体分子上电荷分布的影响,导致离子液体内部阴阳离子之间的相互作用减弱,从而引起离子液体中-NH2上N原子电子云密度增大,使其与CO2作用更容易.CO2在经表面活性剂修饰后的MCM-41负载离子液体[NH2p-mim][PF6]吸附剂上的吸附受扩散控制,其吸附-脱附CO2所需能量较小,经过5次吸附-脱附循环后,其吸附性能仍保持稳定.热重分析结果表明,经表面活性剂修饰后的MCM-41负载离子液体吸附剂在100℃下氮气气氛再生时不会发生性质改变.     

离子液体在CO_2捕集中的应用进展

离子液体具有蒸汽压极低、热稳定性好、热容低和可以根据目标需求进行设计等特性,能克服传统CO2捕集工艺的诸多不足,因而成为目前CO2捕集溶剂的研究热点。本文主要综述了普通离子液体、功能化离子液体、支撑型离子液体膜、聚合型离子液体和离子液体复配溶液在CO2捕集方面的应用研究进展,评述了各种方法的优势和缺点,并在此基础上提出...     

Multi‐Molar Absorption of CO2 by the Activation of Carboxylate Groups in Amino Acid Ionic Liquids

A new strategy for multi‐molar absorption of CO₂ is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron‐withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO₂ very efficiently. An extremely high absorption capacity of CO₂ (up to 1.69 mol mol^?1) in aminopolycarboxylate‐based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum‐chemical calculations confirmed the interactions between two kinds of sites in the anion and CO₂ that resulted in superior CO₂ capacities.     

Thermo- and Photocatalytic Activation of CO2 in Ionic Liquids Nanodomains

Ionic liquids (ILs) are considered to be potential material devices for CO₂ capturing and conversion to energy-adducts. They form a cage (confined-space) around the catalyst providing an ionic nano-container environment which serves as physical-chemical barrier that selectively controls the diffusion of reactants, intermediates, and products to the catalytic active sites via their hydrophobicity and contact ion pairs. Hence, the electronic properties of the catalysts in ILs can be tuned by the proper choice of the IL-cations and anions that strongly influence the residence time/diffusion of the reactants, intermediates, and products in the nano-environment. On the other hand, ILs provide driving force towards photocatalytic redox process to increase the CO₂ photoreduction. By combining ILs with the semiconductor, unique solid semiconductor-liquid commodities are generated that can lower the CO₂ activation energy barrier by modulating the electronic properties of the semiconductor surface. This mini-review provides a brief overview of the recent advances in IL assisted thermal conversion of CO₂ to hydrocarbons, formic acid, methanol, dimethyl carbonate, and cyclic carbonates as well as its photo-conversion to solar fuels.     

超临界CO2/离子液体体系

超临界CO2和离子液体是两种具有优异性能的绿色化学试剂,本文介绍了将两者结合反应,分离体系的物化性质和多种绿色化学过程。利用超临界CO2可以广泛地萃取离子液体中的不挥发性化合物而不导致离子液体及其中催化剂的流失,在加氢、醛化、甲酰化等反应,分离过程中的应用表明,过程具有很好的反应分离特性和环境友好性,应用前景广阔。     

咪唑基离子液体的物理化学性质估算及预测(英文)

根据经验和半经验方程及空隙模型理论,可以估算及预测离子液体在298.15K的物理化学性质.本文讨论了离子液体的分子体积,密度,标准熵,晶格能,表面张力,等张比容,摩尔蒸发焓,空隙体积,空隙率和热膨胀系数.通过实验测得的三种离子液体1-乙基-3-甲基咪唑硫酸乙酯([C2mim][EtSO4)]),1-丁基-3-甲基咪唑硫酸辛酯([C4mim][OcSO4])和1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐([C2mim][NTf2])的密度和表面张力估算了它们的其它物理化学性质.由这三种离子液体的分子体积及等张比容预测了同系列中其它离子液体[Cnmim][EtSO4],[Cnmim][OcSO4]和[Cnmim][NTf2](n=1-6)的分子体积及等张比容,由此计算出它们的密度及表面张力.进而预测了它们的物理化学性质.将预测的离子液体[C4mim][NTf2]和[C2mim][OcSO4]的密度值与文献报导的实验值进行比较,其偏差在实验误差范围内.最后,将由Kabo经验方程计算的七个离子液体[C2mim][EtSO4]、[C4mim][OcSO4]、[C2mim][NTf2]、[C4mim][NTf2]、丁基三甲基铵双三氟甲磺酰亚胺盐([N4111][NTf2])、甲基三辛基铵双三氟甲磺酰亚胺盐([N8881][NTf2])和1-辛基-3-甲基吡啶四氟硼酸盐([m3opy][BF4])的摩尔蒸发焓与由Verevkin简单规则预测的摩尔蒸发焓进行比较,发现两者符合很好.因此,在缺乏密度和表面张力实验数据的情况下,可以用Verevkin简单规则来预测离子液体的摩尔蒸发焓.     

聚合物在咪唑类离子液体中的溶解

离子液体（ILs）具有难挥发、热稳定、宽液程和高电导率等独特优点,在聚合物领域中的应用受到越来越多的关注。由于ILs内部的复杂相互作用力,ILs的溶剂化能力还不能像分子溶剂那样有定量的方法来表征,特别是ILs与聚合物的相容性没有一个统一的判据。本文从咪唑基ILs内部的四个主要相互作用力出发,简述了ILs内部的相互作用对...     

CO2/离子液体体系热力学性质的分子动力学模拟

超临界CO2和离子液体(ILs)是两种绿色溶剂. 离子液体可以溶解超临界CO2, 而超临界CO2不能溶解离子液体. 由此设计构成的CO2/IL二元系统, 同时具备了超临界CO2和离子液体的许多优点: 既可以降低离子液体的粘度, 还便于相分离, 是新型的耦合绿色溶剂. 其物理化学性质对于设计反应、分离等过程非常重要. 因此, 本文以CO2/IL二元系统为研究对象, 通过选择合适的分子力场和系综, 运用分子动力学(MD)模拟方法研究了CO2/[bmim][PF6]、CO2/[bmim][NO3]等体系的热力学性质. 结果表明, CO2对ILs膨胀度的影响非常小, 当CO2摩尔分数为0.5时, ILs膨胀仅为15%. CO2/ILs的扩散系数远小于CO2膨胀甲醇、乙醇溶液的扩散系数. 随着CO2含量的增加, ILs的扩散系数提高, 粘度显著下降, 表明CO2能有效地改善ILs扩散性, 减小其粘度. 因此CO2可用以改善离子液体溶剂体系的传递特性, 增强反应分离过程在其中的进行.