Jin Dongliang, Lu Xiaoqing, Zhang Mingmin, Wei Shuxian, Zhu Qing, Shi Xiaofan, Shao Yang, Wang Weili, Guo Wenyue
College of Science, China University of Petroleum, Qingdao, Shandong 266580, P. R. China.
Phys Chem Chem Phys. 2014 Jun 14;16(22):11037-46. doi: 10.1039/c3cp55107e.
The effects of chemical and structural surface heterogeneity on the CH4 adsorption behaviour on microporous carbons have been investigated using a hybrid theoretical approach, including the use of density functional theory (DFT), molecular dynamics (MD), and grand canonical Monte Carlo (GCMC) simulations. Bader charge analysis is first performed to analyze the surface atomic partial charges. The CH4 adsorption densities in defective and functionalized graphite slit pores are lower than that in the perfect pore according to the MD simulations. Finally, the CH4 adsorption isotherms for the perfect, defective and functionalized slit pores are analyzed using the GCMC simulations in combination with the DFT and MD results. For pores with a defective surface, the adsorption capacities decrease; the embedded functional groups decrease the adsorption capacity at low pressure and enhance it at high pressure. Our results demonstrate the significant effects of chemical and structural surface heterogeneity on the CH4 adsorption and provide a systematic approach to understand the gas adsorption behaviour.
采用包括密度泛函理论（DFT）、分子动力学（MD）和巨正则蒙特卡罗（GCMC）模拟在内的混合理论方法，研究了化学和结构表面非均质性对甲烷在微孔碳上吸附行为的影响。首先进行Bader电荷分析以分析表面原子的部分电荷。根据MD模拟，有缺陷和功能化的石墨狭缝孔中的甲烷吸附密度低于完美孔中的吸附密度。最后，结合DFT和MD结果，使用GCMC模拟分析了完美、有缺陷和功能化狭缝孔的甲烷吸附等温线。对于表面有缺陷的孔，吸附容量降低；嵌入的官能团在低压下降低吸附容量，在高压下提高吸附容量。我们的结果证明了化学和结构表面非均质性对甲烷吸附的显著影响，并提供了一种系统的方法来理解气体吸附行为。
