Applications of DFT Derived Force Fields for Olefin/ Paraffin Separation in MOFs

Grand Canonical Monte Carlo (GCMC) simulations have been widely used to predict adsorption uptakes in nanoporous structures, but the accuracy of these simulations is highly dependent on the quality of the force field used for modeling the intermolecular interactions. Significant advances have been made in recent years in the development of force fields for nanoporous materials from first principles calculations[1].  In this work, we will describe a DFT-based force field development approach for modeling olefin and paraffin interactions in MOFs. The results show that our DFT consistent force fields successfully describe adsorption of linear alkanes and alkenes in MIL-47 (V) and HKUST-1 MOFs. We will discuss the transferability of our HKUST-1 force field to other Cu open metal site MOFs and discuss the potential for using calculations based on these force fields to screen MOFs for olefin/ paraffin separations.

[1] H. Fang, H. Demir, P. Kamakoti, and D. S. Sholl, J. Mater. Chem. A 2 (2014) 274