摘要
采用密度泛函理论的wB97XD方法、RDG函数方法和counterpoise correction理论,研究氮气在干酪根C_(28)H_(14)O和氮掺杂干酪根C_(27)H_(14)ON上的吸附特征。结果表明:N_(2)在干酪根上的活性吸附位点为苯环上方中心位置,吸附能在8~10 kJ·mol^(-1)之间,N_(2)和干酪根之间的相互作用主要是范德华相互作用和空间排斥作用。氮掺杂改变了干酪根的构型和电子云分布,导致含氮杂环不再是稳定的活性吸附位点,增强了排斥作用,使吸附能略有减小。研究结果对理解干酪根吸附小分子的特征有重要意义,能够为页岩气的开采提供理论支持。
Density functional theory wB97XD method,RDG function method and counterpoise correction theory were used to study adsorption characteristics of N_(2) on shale kerogen C28H_(14)O and nitrogen-doped shale kerogen C_(27)H_(14)ON.It shows that the active adsorption site is located on the central position above the benzene ring for N_(2) adsorbed on both kerogen C28H_(14)O and nitrogen-doped kerogen C_(27)H_(14)ON.The adsorption energy is in the range of 8~10 kJ·mol^(-1),which shows that the main interaction between nitrogen molecule and kerogens is van der Waals interaction and steric repulsion.Nitrogen doping changes the geometric configuration and electron cloud distribution of kerogen.As a result,the nitrogen-containing heterocycle is no longer a stable active site.The adsorption energy is a little lower than that of N_(2) adsorbed on C28H_(14)O,but it is still in the range of 8~10 kJ·mol^(-1).The main interaction force between N_(2) and C_(27)H_(14)ON is still van der Waals interaction and steric repulsion.This work is significant for understanding adsorption characteristics of small molecules on kerogens.It provides theoretical support for the exploring of shale gas.
作者
朱元强
靳赛赛
孙青青
ZHU Yuanqiang;JIN Saisai;SUN Qingqing(School of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Oil&Gas Field Applied Chemistry Key Laboratory of Sichuan Province,Chengdu,Sichuan 610500,China)
出处
《计算物理》
CSCD
北大核心
2021年第6期707-712,共6页
Chinese Journal of Computational Physics
