College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China.
College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China.
J Hazard Mater. 2021 May 5;409:124503. doi: 10.1016/j.jhazmat.2020.124503. Epub 2020 Nov 9.
Ionic liquids (ILs) can be used as absorbents and catalysts for NO absorption and conversion due to their low toxicity, low energy consumption and excellent reusability. The capacity and absorption mechanism of NO absorption by ILs are presented in this paper. Generally, NO are physically absorbed by conventional ILs such as imidazolium-based ILs. The absorption capacity is as follows: NO>NO>NO, which is in good agreement with the binding energy between NO and ILs. Furthermore, low temperature, high pressure and large cation volume are favorable for NO absorption. The strategies of enhancing NO capacity through functionalized ILs with metal-containing anions (e.g. [FeCl]), amine groups, sulfonate and carboxylate anions are also concluded. Active N or O sites in functionalized ILs can react with the dimer of NO (NO), resulting in high capacity. Moreover, introducing electron-withdrawing substituents such as chlorine and bromine into carboxylate or sulfonate anions reduces desorption residue. Besides NO absorption, ILs with [NO] can activate NO and efficiently catalyze its conversion into HNO in the presence of O and HO, and have better performance than ILs with [Cl], [Ac] and [CFSO] which is attributed to the strong oxidization capability of [NO]. In addition, low temperature and high O content can further improve NO conversion.
离子液体 (ILs) 由于其低毒性、低能耗和优异的可重复使用性，可用作吸收剂和催化剂，用于吸收和转化 NO。本文介绍了 ILs 对 NO 吸收的容量和吸收机制。通常，NO 通过基于咪唑的 IL 等常规 IL 被物理吸收。吸收能力如下：NO>NO>NO，这与 NO 与 ILs 之间的结合能一致。此外，低温、高压和大阳离子体积有利于 NO 的吸收。通过用含金属阴离子（例如 [FeCl]）、胺基、磺酸盐和羧酸盐阴离子对 ILs 进行功能化来提高 NO 容量的策略也被总结出来。功能化 ILs 中的活性 N 或 O 位点可以与 NO 的二聚体（NO）反应，从而实现高容量。此外，将氯和溴等吸电子取代基引入羧酸盐或磺酸盐阴离子中可以减少解吸残留。除了吸收 NO 之外，具有 [NO] 的 ILs 可以在 O 和 HO 的存在下激活 NO 并有效地催化其转化为 HNO，并且比具有 [Cl]、[Ac] 和 [CFSO] 的 ILs 具有更好的性能，这归因于 [NO] 的强氧化能力。此外，低温和高 O 含量可以进一步提高 NO 的转化率。
