Molecular simulation of hydrogen adsorption in metal-organic frameworks

The capabilities and limitations of the application of molecular simulation techniques to the adsorption of hydrogen in metal-organic frameworks (MOFs) are explored for selected case studies. Force field based grand-canonical Monte Carlo simulations are employed to investigate the adsorption characteristics of three different isoreticular MOFs, resulting in good agreement with experimental findings. The predictive potential of the method is demonstrated for Zn4O(mip)3, a novel system which has not yet been fully characterized experimentally. Further calculations for MOFs with unsaturated metal sites reveal a shortcoming of the simulation technique, as the interaction of hydrogen with these sites is not adequately represented by the potential model. Density functional theory calculations are employed to study the metal-dihydrogen interaction in more detail, making use of a non-periodic model system which is representative for many copper-containing MOFs.