Zeolite-Encapsulated Ir Single Atom Catalysts Toward Efficient and Stable Propane Dehydrogenation

Area of Science:

• Heterogeneous catalysis
• Materials science
• Nanotechnology

Background:

• Single-atom precious metal catalysts offer high metal utilization but suffer from instability under harsh conditions due to sintering.
• Developing stable single-atom catalysts is crucial for their industrial application in demanding catalytic processes.

Purpose of the Study:

• To design and synthesize thermally stable single-atom iridium catalysts encapsulated in Ge-substituted S-1 zeolite (IrGe@S-1).
• To evaluate the performance of IrGe@S-1 catalysts for direct propane dehydrogenation under demanding reaction conditions.

Main Methods:

• Synthesis of Ge-substituted S-1 zeolite encapsulating iridium single atoms.
• Characterization of the catalyst structure and electronic properties.
• Testing propane dehydrogenation activity and stability at high temperatures and space velocities.

Main Results:

• The optimized IrGe@S-1 catalyst achieved a propylene formation rate of 1249.2 molC3H6 gIr−1 h−1 at 600 °C.
• The catalyst demonstrated excellent stability, operating for over 800 hours without regeneration under harsh conditions.
• Ge incorporation enhanced Ir-O-Ge bonding, stabilizing Ir single atoms in a low oxidation state.

Conclusions:

• IrGe@S-1 catalysts represent a breakthrough in creating stable single-atom precious metal catalysts for high-temperature applications.
• The enhanced electronic interaction and isolated active sites contribute to superior activity and selectivity in propane dehydrogenation.
• This work paves the way for the development of robust single-atom catalysts for challenging industrial processes.