Adsorption and Separation of Noble Gases by IRMOF-1: Grand Canonical Monte Carlo Simulations

Abstract

The gas storage capacity of metal-organic frameworks (MOFs) is well-known and has been investigated using both experimental and computational methods. Previous Monte Carlo computer simulations of gas adsorption by MOFs have made several questionable approximations regarding framework-framework and framework-adsorbate interactions: potential parameters from general force fields have been used, and framework atoms were fixed at their crystallographic coordinates (rigid framework). We assess the validity of these approximations with grand canonical Monte Carlo simulations for a well-known Zn-based MOF (IRMOF-1), using potential parameters specifically derived for IRMOF-1. Our approach is validated by comparison with experimental results for hydrogen and xenon adsorption at room temperature. The effects of framework flexibility on the adsorption of noble gases and hydrogen are described, as well as the selectivity of IRMOF-1 for xenon versus other noble gases. At both low temperature (78 K) and room temperature, little difference in gas adsorption is seen between the rigid and flexible force fields. Experimental trends of noble gas inflation curves are also matched by the simulation results. Additionally, we show that IRMOF-1 selectively adsorbs Xe atoms in Xe/Kr and Xe/Ar mixtures, and this preference correlates with the trend in van der Waals parameters for the adsorbate atoms.

Neutral Gases Adsorption With Hydrogen on Silicon Nanotubes: A Fuel Cell Invistegation

“…It is notable that with a diameter less than 2 nm, no condensations are occurred because the system becomes onedimensional 56 , as for SW-CN-Ts. Those explanations are proved with the experimental result for Neon adsorption 57 and molecular simulation results for Helium, Xenon and Argon mixture 59 .…”

A Bio‐Metal–Organic Framework for Highly Selective CO2 Capture: A Molecular Simulation Study

“…As demonstrated in a recent simulation study on the adsorption of noble gases in IRMOF-1, rigid and semi-flexible frameworks gave close results at both low and room temperatures. [40] The LJ interactions were evaluated with a spherical cut off of 13 with the longrange corrections added; the Coulombic interactions were calculated using the Ewald sum. The real/reciprocal space partition parameter and the cut off for reciprocal lattice vectors were chosen to be 0.2 À1 and 8, respectively, to ensure the convergence of the Ewald sum.…”

Initial proof-of-principle for near room temperature Xe and Kr separation from air with MOFs

“…Recently, the research team reported that a MOF known as Ni/DOBDC has a Xe capacity of 4.16 mol/kg at 1 bar and 298 K, which is higher than that of a charcoal carbon . Greathouse et al (2009) used grand canonical Monte Carlo (GCMC) simulation to investigate Xe and Kr separation in a MOF known as IRMOF-1. Ryan and Snurr et al (2011) simulated Xe and Kr separation with several other MOFs with GCMC.…”