A surface modification strategy to prepare hierarchical Beta molecular sieves for glucose dehydration

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Beta molecular sieves are crucial catalysts but suffer porosity loss during modification.
• Introducing mesoporosity often compromises essential microporosity and acidity.

Purpose of the Study:

• To develop a surface modification strategy for Beta molecular sieves that introduces mesoporosity while preserving microporosity and acidity.
• To enhance the catalytic activity of hierarchical Beta molecular sieves for biomass conversion.

Main Methods:

• Selective adsorption of organic alkaline molecules onto Beta molecular sieves prior to NaOH etching.
• Utilizing organic alkaline molecules as protective agents to shield framework aluminum sites.
• Characterization of the modified molecular sieves and evaluation of their catalytic performance in glucose dehydration.

Main Results:

• The surface modification strategy successfully introduced mesoporosity while minimizing microporosity loss.
• Preservation of aluminum atoms led to a higher concentration of acid sites in the hierarchical Beta molecular sieves.
• The modified Beta molecular sieves exhibited enhanced catalytic activity in the dehydration of glucose to 5-hydroxymethylfurfural (5-HMF) via synergistic Brønsted and Lewis acid sites.

Conclusions:

• The proposed method effectively regulates porosity and alleviates acidity loss in Beta molecular sieves.
• Hierarchical Beta molecular sieves are promising catalysts for large molecule-engaged acid-catalyzed reactions, particularly in biomass conversion.