CO2 adsorption in nickel based metal organic framework Ni-DABCO: A density functional theory and grand canonical Monte Carlo study

Abstract

The continuous emissions of greenhouse gases, especially carbon dioxide (CO2), are generating concerns over the negative effects they are having on the planet. The main goal of this project is to understand the adsorption mechanism of CO2 on a nickel-based metal organic framework (MOF) known as Ni-DABCO at the molecular level. We have computationally studied the interaction of CO2 on Ni-DABCO using periodic density functional theory (DFT) and grand canonical Monte Carlo (GCMC). Our periodic DFT calculations indicate that upon interaction, CO2 induces small changes on the structure and electrostatic potential of the Ni-DABCO framework. GCMC simulations were used to generate simulated CO2 and N2 isotherms on Ni- DABCO at 298 K and 77 K, respectively, and our results are in good agreement with experimental data. However, at pressures higher than 10 atm, the simulated isotherm for CO2 underestimates the experimental isotherm, suggesting that Ni-DABCO slightly expands during the adsorption.