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

Area of Science:

• Heterogeneous catalysis
• Nanomaterials
• Chemical reaction engineering

Background:

• Tandem catalysis offers improved chemical processing by coupling multiple reactions.
• Precise spatiotemporal control of reactive intermediates in tandem catalysis remains a significant challenge.
• Propane dehydrogenation (PDH) is an important industrial process, but achieving high selectivity and yield is difficult.

Purpose of the Study:

• To develop a nanostructure for precise control in tandem catalysis.
• To demonstrate selective propane dehydrogenation to propylene using a novel catalytic system.
• To overcome limitations of traditional catalytic approaches for this reaction.

Main Methods:

• Atomic layer deposition was used to grow indium oxide (In2O3) over platinum supported on alumina (Pt/Al2O3).
• The resulting nanostructure was tested for propane dehydrogenation and selective hydrogen combustion.
• Comparative studies were performed with alternative nanostructures (Pt on In2O3, mixed Pt/In2O3).

Main Results:

• The In2O3 over Pt/Al2O3 nanostructure enabled sequential reactions via surface hydrogen atom transfer, achieving selective PDH to propylene.
• This tandem catalysis approach selectively combusted hydrogen using In2O3, preventing excessive hydrocarbon combustion.
• Alternative nanostructures resulted in preferential propane combustion, highlighting the importance of the specific geometry.

Conclusions:

• The nanoscale overcoating geometry is crucial for achieving selective tandem catalysis.
• This method provides rapid and stable oxidative dehydrogenation of propane with high per-pass yields.
• The demonstrated tandem catalysis approach is a viable strategy for highly selective performance in challenging catalytic reactions.