SYNTHESIS OF ZEOLITES WITH INTERCONNECTED NANOSHEETS

Smart overview of the Invention

Interconnected zeolite nanosheets are synthesized using MEL or MFI-type zeolites as crystalline seeds, resulting in structures similar to self-pillared pentasil zeolites. This innovative method eliminates the need for organic or branching templates during crystallization, marking a significant advancement in the synthesis of hierarchical zeolites.

Background and Importance

Zeolite catalysts are crucial in various industrial applications, but their performance can be limited by diffusion constraints within their microporous structures. Traditional methods to enhance mass transport often rely on organic structure-directing agents and multiple synthesis steps, which can hinder yield and scalability. Developing a more efficient synthesis method is essential for improving zeolite catalytic performance in reactions such as alkylation and biomass conversion.

Methodology

The disclosed method employs an organic structure-directing-agent (OSDA)-free approach, utilizing a seed-assisted technique to create interconnected nanosheets of pentasil zeolites. By introducing calcined zeolite seed crystals into an organic-free growth medium, the synthesis facilitates high product yields and concentrations of acid sites, leading to enhanced catalytic activity compared to conventional ZSM-5 catalysts.

Characterization of the Resulting Zeolites

The synthesized zeolites exhibit a predominantly MFI-type structure with significant external surface area and high percentages of external acid sites. Analysis reveals a unique "house of cards" morphology with an average thickness of approximately 30 nm, enhancing access to catalytic sites. The interconnected nanosheets display a hierarchical arrangement that contributes to improved mass transport and catalytic efficiency.

Applications and Future Implications

The resulting zeolite nanosheets can be utilized as catalysts in various chemical processes, including alkylation and methanol-to-hydrocarbons conversions. This OSDA-free synthesis method not only simplifies the production process but also holds promise for commercial viability, potentially transforming the landscape of zeolite applications in industrial chemistry.