This study investigates the factors that enhance the selective adsorption performance of Xe and Kr in Metal Organic Frameworks (MOFs) using Grand Canonical Monte Carlo simulation. Simulations were conducted with MOFs such as SBMOF-1, UiO-66, and MOF-303, which have large pores capable of trapping Xe and Kr inside their structures. In the case of MOF-303, doping with copper increased adsorption and selectivity performance.
To further investigate the effect of different doping metals on MOF-303, additional atoms such as silver and gold were used in simulations, as they belong to the same group in the periodic table as copper. The simulation results showed that Cu-doped MOF-303 exhibited a high Xe adsorption capacity per unit mass. However, Ag-doped MOF-303 demonstrated better adsorption performance per unit cell than Cu-doped MOF-303 due to larger Van der Waals interaction energy with Xe when Ag was doped. Additionally, Ag-doped MOF-303 showed better adsorption than Au-doped MOF-303 because Ag-doped MOF-303 has more pores suitable for Xe and Kr adsorption than Au-doped MOF-303.
The simulation results indicate that when different metals are doped into the MOF structure, higher adsorption performance is achieved with metals that exhibit stronger Van der Waals interaction energy with the adsorbate and when the MOF contains more pores larger than the adsorbate atoms.