Journal Article

IMPULSE-2023-00067

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Correlation between structure and dynamics of CO$_2$ confined in Mg-MOF-74 and the role of inter-crystalline space: A molecular dynamics simulation study

Dhiman, I. ; Berg, M. C.MLZ* ; Cole, D. R. ; Gautam, S.

2023
Elsevier Amsterdam

Please use a persistent id in citations: doi:10.1016/j.apsusc.2022.155909

Abstract: Mg-MOF-74 is a metal–organic framework (MOF) with a high capacity for CO2 adsorption. Given the importance of CO2 confinement in Mg-MOF-74 for capture and storage applications, it is important to understand CO2 behavior in Mg-MOF-74. While most molecular simulation studies use ideal single crystal models of nano-porous substrates, the existence of inter-crystalline space is shown to have profound effects on the adsorption, structure and dynamics of the adsorbed fluid. Here we report a molecular dynamics simulation study at 300 K, of CO2 confined in Mg-MOF-74 with inter-crystalline spacing of different widths. Six strong sites of CO2 adsorption are found at the periphery of the Mg-MOF-74 pores in addition to a relatively weak adsorption at the pore center. On insertion of inter-crystalline spacing, additional sites of strong adsorption are seen close to the pore opening, which delocalize as the inter-crystalline space is widened while adsorption in the pore center grows. This redistribution has important implications for the dynamics of CO2. With wider inter-crystalline spacing, anomalous loading dependence of translational diffusivity is observed. In general, inter-crystalline spacing suppresses the rotational motion of CO2. Translational motion, however, exhibits an enhancement on the introduction of inter-crystalline space but gets suppressed when this space is widened.

Keyword(s): Chemical Reactions and Advanced Materials (1st) ; Chemistry (2nd)

---

Contributing Institute(s):

1. J-NSE (J-NSE)

Experiment(s):

1. No specific instrument

---

Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---