Sub-Nanometer Catalyst Clusters for Propane Dehydrogenation

Propane dehydrogenation (PDH) is used to produce propene, which is the primary building block for many commercial plastics. The catalyst most commonly used for this reaction is platinum. Due to rising demand for propene, an alternative catalyst is being sought due to platinum’s high cost. Alternatives might involve very small platinum particles as well as particles composed of different atoms. For this purpose, we have performed a computational study of the PDH reaction with a 4 atom platinum cluster (Pt4) and several different 4-atom transition metal cluster (TM4) catalysts on a graphene support. We have computed the equilibrium structures of the Pt4 and TM4 clusters on both single-and double-vacancy sites and have calculated the complete PDH reaction pathway for each case. This allowed us to study the effect of the graphene support on catalytic activity. We have also calculated the PDH reaction pathway for larger Ptx clusters, where x = 5-14, in order to study the effect of particle size on catalytic activity. These results help clarify the relationship between the PDH activation energy and the propane binding energy and overall reaction energy and may aid in the design of new potential catalysts for the PDH reaction