Large-scale simulations of CO2 diffusion in metal–organic frameworks with open Cu sites

Autor: Tongan Yan, Minman Tong, Chongli Zhong, Yandong Guo, Dahuan Liu, Qingyuan Yang
Rok vydání: 2022
Předmět:
Zdroj: Chinese Journal of Chemical Engineering. 42:1-9
ISSN: 1004-9541
DOI: 10.1016/j.cjche.2021.08.013
Popis: Understanding CO2 diffusion behavior in functional nanoporous materials is beneficial for improving the CO2 adsorption, separation, and conversion performances. However, it is a great challenge for studying the diffusion process in experiments. Herein, CO2 diffusion in 962 metal–organic frameworks (MOFs) with open Cu sites was systematically investigated by theoretical methods in the combination of molecular dynamic simulations and density functional theory (DFT) calculations. A specific force field was derived from DFT-D2 method combined with Grimme's dispersion-corrected (D2) density functional to well describe the interaction energies between Cu and CO2. It is observed that the suitable topology is conductive to CO2 diffusion, and 2D-MOFs are more flexible in tuning and balancing the CO2 adsorption and diffusion behaviors than 3D-MOFs. In addition, analysis of diffusive trajectories and the residence times on different positions indicate that CO2 diffusion is mainly along with the frameworks in these MOFs, jumping from one strong adsorption site to another. It is also influenced by the electrostatic interaction of the frameworks. Therefore, the obtained information may provide useful guidance for the rational design and synthesis of MOFs with enhanced CO2 diffusion performance for specific applications.
Databáze: OpenAIRE