Molecular simulation of gas adsorption and diffusion in a breathing MOF using a rigid force field

Molecular simulation of gas adsorption and diffusion in a breathing MOF using a rigid force field

García-Pérez, E.
Serra-Crespo, P.
Hamad, S.
Kapteijn, F.
Gascon, J.

Applied Sciences

ChemE/Catalysis Engineering

2014-06-11

Simulation of gas adsorption in flexible porous materials is still limited by the slow progress in the development of flexible force fields. Moreover, the high computational cost of such flexible force fields may be a drawback even when they are fully developed. In this work, molecular simulations of gas adsorption and diffusion of carbon dioxide and methane in NH2-MIL-53(Al) are carried out using a linear combination of two crystallographic structures with rigid force fields. Once the interactions of carbon dioxide molecules and the bridging hydroxyls groups of the framework are optimized, an excellent match is found for simulations and experimental data for the adsorption of methane and carbon dioxide, including the stepwise uptake due to the breathing effect. In addition, diffusivities of pure components are calculated. The pore expansion by the breathing effect influences the self-diffusion mechanism and much higher diffusivities are observed at relatively high adsorbate loadings. This work demonstrates that using a rigid force field combined with a minimum number of experiments, reproduces adsorption and simulates diffusion of carbon dioxide and methane in the flexible metal–organic framework NH2-MIL-53(Al).

Gold for Gold
Open Access

http://resolver.tudelft.nl/uuid:a49df296-ce2e-4926-a9cb-bbdf223a3124

https://doi.org/10.1039/C3CP55416C

RSC Publishing

1463-9076

Phys. Chem. Chem. Phys., 2014

Institutional Repository

journal article

(c) 2014 RSC