Chemical Engineering Department Seminar Series

“MOLECULAR MODELING OF ADSORPTION AND CATALYSIS IN NANOCAVITIES FORMED BY SUPRAMOLECULAR SELF-ASSEMBLY”

Metal-organic frameworks (MOFs) are a new class of nanoporous materials synthesized in a “building-block” approach by self-assembly of metal or metal-oxide vertices interconnected by rigid organic linker molecules.  The rational synthesis approach opens up the possibility of incorporating a wide variety of functional groups into the materials, and these materials may lead to new advances in adsorption separations, gas storage, sensing, and catalysis.  Because of the predictability of the synthetic routes and the nearly infinite number of variations possible, molecular modeling is an attractive tool for screening new structures before they are synthesized.  Modeling can also provide insight into the molecular-level details that lead to observed macroscopic properties.

This talk will focus on molecular modeling of adsorption and catalysis in MOFs and related nanocavities formed by self-assembly.  We will show that atomistic Monte Carlo simulations can predict adsorption of simple gases in a range of MOFs in good agreement with experiment.  This paves the way for using simulation to screen existing and hypothetical MOFs for adsorption separations.  Modeling of catalysis requires quantum mechanical methods.  However, treating an entire MOF cavity quantum mechanically can be prohibitively expensive.  Hybrid methods that treat a central region quantum mechanically while treating surrounding atoms with classical models are a promising way to include both the chemistry at the active site and the effects of the surrounding MOF framework.  We will present preliminary results for catalytically active MOFs and related, discrete “molecular-square” cavities.