DFT Study on Thermodynamic Parameters of CO2 Absorption into Aqueous Solution of Aliphatic Amines  

脂肪胺水溶液吸收CO2的热力学参数的密度泛函理论研究

作　　者：Monireh Hajmalek Hossein Aghaie Karim Zare Mehran Aghaie 

机构地区：[1]伊朗伊斯兰阿扎德大学科学研究部化学系,德黑兰 [2]伊朗萨伊德比赫什蒂大学理学院化学系,德黑兰 [3]伊朗伊斯兰阿扎德大学德黑兰分校化学部,德黑兰

出　　处：《Chinese Journal of Chemical Physics》2014年第6期672-678,I0003,共8页化学物理学报（英文）

摘　　要：Using density functional theory （DFT）, the thermodynamic parameters of the CO2 absorp-tion into the aqueous solution of the aliphatic amines including some alkylamines, alka-nolamines, diamines and a type of aminoamide were calculated. The geometry optimiza-tion and the calculation of vibrational frequencies in the gas phase were performed at the B3LYP/6-311＋ G（d,p） level of theory. Moreover, the standard solvation free energies of the studied species were computed upon the solution phase optimized geometries through the latest continuum solvation model （SMD/IEF-PCM） at the HF/6-31G（d） level of theory. With this approach, two important properties of the CO2 absorption into the aqueous so-lutions of the studied amines were evaluated： the acid dissociation constant （pKa） of the parent amines and the standard enthalpy change （ΔH^φabs） related to the CO2 absorption process. A roughly linear relationship was observed between pKa and ΔH^φabs. This finding suggests that a raise in the basicity of an amine leads to an increase in the heat released in CO2 absorption and consequently in the required energy for the regeneration of amine.

关 键 词：Density functional theory AMINE CO2 absorption Heat of absorption SMD solvation model 

分 类 号：O[理学]