We performed a three layer ONIOM computation to model the interaction of a Cu2+ cation with an aluminum modified FAU zeolite. The high layer (HL) was model at the B3LYP/6-31+G(d) level of theory, the medium layer (ML) with the PM6 semi-empirical method and the low layer (LL) with the universal force filed (UFF). We found that the best representation of a real system is by using a symmetric T5 cluster as our HL embedded on a T14 (ML) which is also embedded on the zeolite framework (LL). We also found that it is very important to take into account the charges of the molecular mechanics part in our computations. These results showed that Cu2+ adsorbs in a three-hollow site, with one of the oxygen-copper distances significantly shorter (2.15788 �) than the other two. According to NBO analysis this shorter distance is due to the formation of an ionic bond, while the other two are due to donor-acceptor type interactions between the oxygen lone pairs and the non-filled valence orbital of copper. We used ammonia as a test molecule of our system. Upon adsorption of ammonia, the copper-zeolite interaction changes to a bridge adsorption between copper and two oxygen atoms. While the ammonia forms a single bond with copper via the nitrogen atom. These results have implications on the design of transition metal-zeolite catalyst.

Implementation of a three layer ONIOM method to model the interaction of Cu<sup>2+</sup> with an aluminum-modified FAU zeolite

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Implementation of a three layer ONIOM method to model the interaction of Cu2+ with an aluminum-modified FAU zeolite

Implementation of a three layer ONIOM method to model the interaction of Cu²⁺ with an aluminum-modified FAU zeolite