基于分子模拟的新型双阳离子质子型离子液体捕集CO_(2)研究  

Revealing CO_(2) capture by a novel dual-cation protic ionic liquid using molecular simulation

作　　者：张奇 张睿[1] 郑涛 曹欣[1] 刘植昌[1] 刘海燕[1] 徐春明[1] 张荣[2] 孟祥海[1] ZHANG Qi;ZHANG Rui;ZHENG Tao;CAO Xin;LIU Zhichang;LIU Haiyan;XU Chunming;ZHANG Rong;MENG Xianghai(State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,Shanxi,China)

机构地区：[1]中国石油大学(北京)重质油全国重点实验室,北京102249 [2]中国科学院山西煤炭化学研究所煤炭高效低碳利用全国重点实验室,山西太原030001

出　　处：《化工学报》2025年第2期797-811,共15页CIESC Journal

基　　金：国家自然科学基金项目(22021004,22078359);煤炭高效低碳利用全国重点实验室开放课题基金项目(J24-25-202)。

摘　　要：有机超强碱质子离子液体作为一种绿色溶剂,在CO_(2)捕集领域展现出独特优势。选择由1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)和N-叔丁基二乙醇胺(NtBuDEA)反应生成的有机超强碱双阳离子质子型离子液体[DBUH]_(2)[NtBuDEA]为吸收剂,通过密度泛函理论和分子动力学模拟分析其与CO_(2)之间的微观结构、作用机理及吸收过程。研究发现,阴离子[NtBuDEA]^(2-)的烷基氧负离子在CO_(2)吸收过程中发挥关键作用,与CO_(2)发生化学键合作用,生成烷基碳酸盐[NtBuDEACOO]^(2-)。CO_(2)分子从气相扩散到吸收剂表面并在气/液界面处聚集,其吸收量在达到最大值后围绕平均值波动。温度和压力是影响CO_(2)吸收的关键因素,降低吸收温度和提高CO_(2)分压有利于CO_(2)的捕集。水的存在虽降低了吸收剂与CO_(2)的相互作用能,却提高了CO_(2)的传输性能。As a green solvent,organic superbase proton-type ionic liquids show unique advantages in the field of CO_(2)capture.In this work,we investigated the organic super base dual-cation protic ionic liquid[DBUH]_(2)[NtBuDEA],synthesized via the reaction between 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)and N-tert-butyl-diethanolamine(NtBuDEA).The microstructure,action mechanism and absorption process between the[DBUH]_(2)[NtBuDEA]and CO_(2)were analyzed by density functional theory(DFT)and molecular dynamics(MD)simulation.The results demonstrated that the anion[NtBuDEA]^(2-)is critical for CO_(2)absorption,engaging in chemical bonding with CO_(2)to form the alkyl carbonate[NtBuDEACOO]^(2-).Additionally,CO_(2)molecules diffuse rapidly from the gas phase to the surface of absorbent and accumulate at the gas/absorbent interface.The amount of absorbed CO_(2)fluctuates around the average value after reaching maximum absorption.Temperature and pressure are key factors influencing CO_(2)uptake and it is favorable for CO_(2)capture through decreasing the reaction temperature and increasing the CO_(2)partial pressure.Although the existence of water reduces the interaction energy between the absorbent and CO_(2),it enhances CO_(2)transfer performance,particularly under high pressure conditions,where the CO_(2)absorption capacity per molar ionic liquid in water-containing ionic liquids surpasses that in pure ionic liquids.

关 键 词：碳捕集 离子液体 密度泛函理论 分子动力学 微观机理 

分 类 号：TQ028[化学工程]