(583b) Combining Ab Initio and Classical Molecular Dynamics Simulations to Predict the Implication of Charged Osdas on of Al Siting Preferences in CHA.

Zeolite materials play important roles on catalysis and separation processes. While the aluminum site in zeolite serves as the Brønsted Acid site and catalysis center, the distribution and the location of aluminum sites are critical to zeolite properties. With the presence of organic structure directing agent (OSDA), not only the pore shape and the zeolite type are determined, the aluminum composition and distributions are also largely affected. Based on our previous work of using first principle density functional theory (DFT) calculations, we seek to apply classical molecular dynamics (MD) simulations in the current work, which can significantly reduce computational costs and allow us to study systems in larger sizes. We first develop a classical model rooted in DFT calculations and then use it to predict the aluminum distribution in selected zeolite structures with certain types of OSDAs. Our classical MD model correlates well with DFT calculations and is able to give reasonable predictions against available experimental results.