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 Pt 13 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.