Publication in Nature Chemistry

Together with the group of Laura Gagliardi we studied the adsorption of CO2 in the metal organic framework MOF74. 

Coverage of this work at:

University of Minnesota

Lawrence Berkeley National Laboratory

The Energy Collective

no alt info

A. Dzubak, L.-C. Lin, J. Kim, J. A. Swisher, R. Poloni, S. N. Maximoff, B. Smit, and L. Gagliardi, Ab-initio Carbon Capture in Open-Site Metal Organic Frameworks Nat Chem  (2012)

Cover of PCCP

We ended up on the cover with our molecular simulations of Forrest on diffusion in zeolites.

M. K. F. Abouelnasr and B. Smit, Diffusion in confinement: kinetic simulations of self- and collective diffusion behavior of adsorbed gases PCCP 14 (33), 11600 (2012)



The self- and collective-diffusion behaviors of adsorbed methane, helium, and isobutane in zeolite frameworks LTA, MFI, AFI, and SAS were examined at various concentrations using a range of molecular simulation techniques including Molecular Dynamics (MD), Monte Carlo (MC), Bennett–Chandler (BC), and kinetic Monte Carlo (kMC). This paper has three main results. (1) A novel model for the process of adsorbate movement between two large cages was created, allowing the formulation of a mixing rule for the re-crossing coefficient between two cages of unequal loading. The predictions from this mixing rule were found to agree quantitatively with explicit simulations. (2) A new approach to the dynamically corrected Transition State Theory method to analytically calculate self-diffusion properties was developed, explicitly accounting for nanoscale fluctuations in concentration. This approach was demonstrated to quantitatively agree with previous methods, but is uniquely suited to be adapted to a kMC simulation that can simulate the collective-diffusion behavior. (3) While at low and moderate loadings the self- and collective-diffusion behaviors in LTA are observed to coincide, at higher concentrations they diverge. A change in the adsorbate packing scheme was shown to cause this divergence, a trait which is replicated in a kMC simulation that explicitly models this behavior. These phenomena were further investigated for isobutane in zeolite MFI, where MD results showed a separation in self- and collective- diffusion behavior that was reproduced with kMC simulations.

© Berend Smit 2019