Solvation and Mobilization of Metal Cations in Zeolites
Abstract: Metal-exchanged zeolites are solid nanoporous materials utilized for selective catalytic reduction of NOx (SCR), methane to methanol conversion, passive NOx adsorption (PNA), and a number of other catalytic and non-catalytic industrial applications. One critical feature of these materials is the solvation of mononuclear exchanged metal ions at low temperatures (<573 K) to create mobile cationic metal-adsorbate coordination complexes that are bonded ionically to anionic zeolite framework sites generated from Al substitution.
In this seminar, Professor Paolucci will describe two examples, Cu-CHA (SCR) and Pd-CHA (PNA), where reactant solvation and active site mobility are integral to material performance. A combination of ab initio molecular dynamics and statistical mechanical models are used to describe the dynamic response of the active sites to varying gas exposure conditions and validate the results with spectroscopic and kinetic experiments. The mobility of these cationic sites has direct entropic and mechanistic consequences. These examples will highlight some general consequences of cation mobility in metal-exchanged zeolites. The results also reveal a more general phenomenon of reactions catalyzed under conditions that facilitate solvation and mobilization of active sites.
UVA Chemical Engineering professor Chris Paolucci specializes in computational catalysis, quantum chemical calculations, modeling of material synthesis and deactivation, molecular dynamics and Monte Carlo simulations.
Please join us at 3:30pm prior to the seminar for Tea Time in Wilsdorf Room 109A.