Alkaline-Assisted Excessive Impregnation for Enhancing Au Nanoparticle Loading on the TS-1 Zeolite

Area of Science:

• Heterogeneous catalysis
• Nanomaterials
• Green chemistry

Background:

• Direct epoxidation of propylene (C3H6) using H2 and O2 over Au/TS-1 is a key reaction for propylene oxide (PO) production.
• Traditional methods for loading gold nanoparticles (Au) onto TS-1 catalysts limit catalytic performance.
• Achieving high efficiency and selectivity in this reaction remains a significant challenge.

Purpose of the Study:

• To develop an improved method for loading Au nanoparticles onto TS-1 catalysts.
• To enhance the catalytic performance, selectivity, and stability of Au/TS-1 for direct propylene epoxidation.
• To overcome limitations of traditional nanoparticle loading techniques.

Main Methods:

• Utilized alkaline-assisted excessive impregnation to load Au nanoparticles onto TS-1.
• This method effectively removed chloride ions (Cl-) from the precursor, improving Au loading efficiency.
• Characterized the catalyst to understand changes in hydrophobicity, surface acidity, and radical environment.

Main Results:

• The developed Au/TS-1-AEI catalyst demonstrated significantly improved C3H6 conversion (8.0%).
• Achieved high PO selectivity (96.7%) and excellent stability (>100 hours).
• The new method prevented abnormal nanograin growth and optimized catalyst properties.

Conclusions:

• Alkaline-assisted excessive impregnation is a superior method for preparing Au/TS-1 catalysts for direct propylene epoxidation.
• The enhanced catalyst properties (hydrophobicity, acidity, radical environment) contribute to improved performance.
• This advancement offers a more efficient and stable route for propylene oxide synthesis.