Pt Cluster Catalysts and Alkane to Aromatic Conversion Evaluated Using a Combination of Swarm Intelligence and Density Functional Theory

Alkane dehydrocyclization to aromatics using Pt clusters
embedded
in a zeolite framework is an important industrially relevant catalytic
system. The catalyst and mechanistic details of this system are not
fully known. Here, we report density functional theory (DFT) calculations
combined with a swarm intelligence algorithm to determine Pt positioning
and interaction with the zeolite framework and detailed comparison
of reaction pathways. A Pt13 cluster, as well as smaller
and larger clusters, was used for evaluation of transition states
and reaction pathways, and this revealed that the pathway involving
C–H activation, cyclization, and then dehydrogenation is rate
limited by cyclization and our calculated barriers are close to experimentally
reported kinetic barriers.