The Behavior of Isopropanol in Nu-1000 MOF: Experiments and Molecular Dynamics Simulations

A. School of Chemical, Biological and Materials Engineering, University of Oklahoma USA

B. Department of Physics and Astronomy, The University of North Carolina, Chapel Hill, NC 27599, United States

Metal organic frameworks (MOFs) are a novel class of catalysts characterized by high porosities and high surface areas that, due to their competitive adsorption properties, present as promising instruments for the decontamination of chemical warfare agents (CWAs). Despite their auspicious characteristics, however, many MOFs contain pore apertures that are smaller than or comparable to the molecular sizes of CWAs. In order to elucidate design rules for the applicable success of these catalysts, evaluation of micropore accessibility and diffusivity of toxic chemicals in MOFs is urgently needed. In this work, we use isopropanol (IPA) as a simulant and perform molecular dynamics simulations and ab initio density functional theory (DFT) calculations to understand the behavior of IPA in NU-1000. Both pure IPA and IPA/Water mixtures have been investigated. Properties including adsorption, diffusion and competitive interactions between IPA, Water and NU-1000 have been obtained computationally. The simulations results have been compared with in situ nuclear magnetic resonance (NMR) experimental results to reveal the fundamental roles of pore chemistry and pore geometry.