Tandem In₂O₃-Pt/Al₂O₃ catalyst for coupling of propane dehydrogenation to selective H₂ combustion.

Abstract

Tandem catalysis couples multiple reactions and promises to improve chemical processing, but precise spatiotemporal control over reactive intermediates remains elusive. We used atomic layer deposition to grow In₂O₃ over Pt/Al₂O₃, and this nanostructure kinetically couples the domains through surface hydrogen atom transfer, resulting in propane dehydrogenation (PDH) to propylene by platinum, then selective hydrogen combustion by In₂O₃, without excessive hydrocarbon combustion. Other nanostructures, including platinum on In₂O₃ or platinum mixed with In₂O₃, favor propane combustion because they cannot organize the reactions sequentially. The net effect is rapid and stable oxidative dehydrogenation of propane at high per-pass yields exceeding the PDH equilibrium. Tandem catalysis using this nanoscale overcoating geometry is validated as an opportunity for highly selective catalytic performance in a grand challenge reaction.