Molecular dynamics simulation of acetylene diffusion in MOF-508a and MOF-508b

Abstract

In this work, the MD simulation was used to find how the diffusion of acetylene molecules is affected by the type of MOF structure, temperature and loading. Diffusion of 4, 6, and 8 acetylene molecules in MOF-508a and MOF-508b were investigated in the temperature range of 300–900 K. The mean square displacement, the self-diffusion and the activation energies were calculated for each loading in different temperatures. The results indicated that the self-diffusion in MOF-508a is much higher than MOF-508b and increases with increasing the temperature and loading. The calculated binding energy decreases by the temperature and increases by the loading. The height of RDF peak of acetylene molecules reduces with temperature and loading and also shifts a little toward the higher distances in both MOFs. Comparing our results with similar studies on Zeolites indicated that the self-diffusion of acetylene molecules in MOF-508a and MOF-508b is in order of the self-diffusion in zeolites.