The Synthesis Of Amino-functionalized Ionic Liquids And Their Application In The Capture Of Acide Gases

The environmental problems and other serious dangers to human health caused by flue gases such as CO2/NO have attracted worldwide attention.Owing to their excellent physicochemical properties such as high thermal stabilities,wide liquid temperature ranges,non-volatile and excellent designable properties,ionic liquids(ILs)are promising and environmentally friendly absorbents for capturing efficiently flue gas in industrial application.Herein,we designed and developed a series of amino-functionalized ionic liquids with specific structure to depict the absorption mechanism and improve the capture capacity of CO2 or NO.Firstly,we synthesized amino-functionalized ionic liquids with varied basic anion to study the influence of anion basicity on CO2 capture,such as[P66614][Tau],[P66614][His],[P66614][MA-BenIm].Combining the DFT calculations and spectrum investigation,for[P66614][His],the strong basicity of the imidazole anion inhibited the activity of the amino group in absorbing CO2.Meanwhile the activity of the imidazole anion capturing CO2 with tethering amino group would be inactive;For[P66614][Tau]with weakly basic anion-sulfonic acid,only amino group as the active site can interact with CO2;Only when the anion and amine group with ability equal in CO2 capture,such as[P66614][MA-BenIm],the two active sites were able to effectively participate in CO2 chemical trapping to achieve higher absorption capacity(1.12 mol CO2/mol IL,30?/1 bar).[P66614][MA-BenIm]has an outstanding adsorption capacity and excellent reversibility.Secondly,a new strategy for improving the capture of NO through designing anion-amino bifunctionalization ionic liquids with multiple interaction sites to achieve highly efficient NO capture was proposed.[P66614][His]exhibited a ultrahigh absorption capacity up to 6.2 mol NO per mol IL at 30?.Through a combination of desorption experiments(80 ? and N2 purge),DFT calculations and TGA,the results indicated that[P66614][His]exhibited well thermal stability,low desorption energy consumption,high effective absorption capacity and excellent recycling performance,which desorption started at 80 ? with a desorption capacity of 2 mol NO/mol IL.