Multi-molar CO2 capture beyond the direct Lewis acid–base interaction mechanism

文献情報

出版日 2020-04-20

DOI 10.1039/D0CP01493A

インパクトファクター 3.676

著者

Chenchen Li, Dongmei Lu, Chao Wu

原文を見る

要旨

Some singly charged ionic liquids (ILs) have been reported to absorb multi-molar CO2. However, the conventional acid(CO2)–base(anion) interaction picture leads to too weak CO2 binding to support the high uptake. Later, a so-called “cation-channel” mechanism assuming the cation-to-anion proton transfer successfully explains the over equimolar CO2 uptake of some phosphonium-based ILs. Here, by employing the density functional theory (DFT) calculations, we extend the proton transfer mechanism to incorporate imidazole- and ammonium-based ILs as well. For imidazole-based ILs, carbene molecules formed after the proton transfer can react strongly with CO2. More importantly, for ammonium-based ILs, the proton transfer process is feasible only with the help of CO2 molecules. Furthermore, compared to the one IL ion pair model, the model consisting of two IL ion pairs can result in stronger CO2 absorption because it can describe the intermolecular hydrogen bonds more appropriately, especially after incorporating CO2 molecules. The relative acidity and basicity of cations and anions in ILs may be crucial for understanding their functionalization as ILs.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.