Doe Nanoporous Materials Genome Center Kick off Meeting | University of Minnesota Poster Session Abstracts Title: Adsorption of Polar Compounds from Gas and Solution Phases onto Zeolites

Over the past 20 years, molecular simulation studies have been widely utilized to investigate the adsorption of non-polar and weakly polar species from the gas phase onto zeolites. In contrast, investigations of the adsorption of polar and hydrogen-bonding compounds from a solution phase are very sparse because of a lack of transferable force fields and efficient simulation algorithms for these more complex systems. Here, we present methodological developments that overcome these limitations and apply the new methodologies to adsorptive separations of practical interest. First, the TraPPE-zeo (transferable potentials for phase equilibria-zeolites) force field is parameterized and shown to be capable of predicting the adsorption isotherms for n-alkanes, carbon dioxide, alcohols, and water with high accuracy. Second, a simulation strategy is optimized that combines configurational-bias Monte Carlo (CBMC) techniques and the Gibbs ensemble (GE) to allows for the investigation of adsorption from solution phases over the whole composition range (without reliance on empirical activity models) and any number of sorbate species. Third, the TraPPE-zeo force field and CBMC-GE approach are applied to investigate the multi-component adsorption of water, alcohols, and other oxygenated compounds. Silicalite-1 is found to be highly selective for alcohols over water. The ideal adsorbed solution theory substantially under predicts the amount of sorbed water and leads to very large errors for the sorption selectivity.