Highly efficient catalytic propane dehydrogenation driven by MFI zeolite defect sites.

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Propane dehydrogenation (PDH) is vital for propylene production.
• Catalyst activity and stability are key challenges in PDH.
• Existing methods often require co-feeding gases like H2 or CO2.

Purpose of the Study:

• To engineer a robust catalyst for efficient and stable propane dehydrogenation.
• To overcome the activity-selectivity-stability trade-off in PDH.
• To elucidate the reaction mechanism for improved catalyst design.

Main Methods:

• Synthesis of a Pt@Sn-MFI catalyst with a wormhole-type structure.
• Characterization using advanced techniques.
• Isotope-labeling experiments and theoretical calculations.
• Evaluation of catalytic performance under PDH conditions.

Main Results:

• Achieved near-thermodynamic equilibrium conversion and ≥98.5% propylene selectivity.
• Demonstrated high apparent forward rate coefficient (1064.5 molC3H6 gPt-1h-1bar-1).
• Exhibited stability for over 120 hours without co-feeding H2 or CO2.
• Identified a hydroxy-assisted PDH pathway.

Conclusions:

• The engineered Pt@Sn-MFI catalyst offers superior performance in PDH.
• Synergy between Pt sites and zeolite defects (hydroxyl groups) enhances catalytic activity and stability.
• The hydroxy-assisted mechanism provides insights for future catalyst development.