Mechanism and Kinetics of <i>n</i>-Butane Dehydrogenation to 1,3-Butadiene Catalyzed by Isolated Pt Sites Grafted onto ≡SiOZn–OH Nests in Dealuminated Zeolite Beta

An interest in the on-purpose production of 1,3-butadiene (1,3-BD) has grown, as a consequence decline naphtha cracking for ethene and propene, products that can now be produced economically by thermal dehydrogenation ethane propane contained natural gas. In this study, mechanism kinetics n-butane to 1,3-BD are explored over atomically distributed Pt sites grafted onto dealuminated zeolite BEA (DeAlBEA) form (≡Si–O–Zn)4–6Pt complexes. Reaction carried out at 823 K with 2.53 kPa n-butane/He weight-hourly space velocity (WHSV) 14.5 h–1 turnover frequency 0.45 mol (mol Pt)−1 s–1. Space-time studies identification reaction intermediates suggest first undergoes primarily 1-butene, which then rapidly isomerizes produce an equilibrated mixture 1-butene 2-butene. 1-Butene secondary 1,3-BD. We report, here, detailed study butenes isolated sites. Both reactions exhibit Langmuir–Hinshelwood dependence on partial pressures, respectively. Comparison effective forward rate constants (k1f) butene (k2f) shows DeAlBEA very high activity sequential relative other Pt-based catalysts previously reported.