Synthesis of a high-silica intersecting-large-pore zeolite using hydrogen-bond-assisted structure-directing agents

Area of Science:

• Materials Science
• Inorganic Chemistry
• Nanotechnology

Background:

• Targeted synthesis of zeolites with specific pore structures remains a significant challenge in synthetic chemistry.
• Developing novel synthetic strategies is crucial for advancing zeolite applications.

Purpose of the Study:

• To introduce a new zeolite synthesis strategy for preparing high-silica and all-silica large-pore zeolites.
• To characterize the newly synthesized zeolite NUD-19 and evaluate its potential applications.

Main Methods:

• Utilizing hydroxyl-containing organic cations as structure-directing agents.
• Employing low-temperature aging to facilitate hydrogen-bonding assemblies.
• Characterizing the resulting zeolite structure and porosity.

Main Results:

• Successfully synthesized a novel high-silica, all-silica large-pore zeolite, designated NUD-19.
• NUD-19 features a 3D intersecting 12-membered-ring pore network with 1.18 nm cavities.
• The zeolite is thermally stable up to 550 °C and exhibits hierarchical porosity (micro-, meso-, and macropores).

Conclusions:

• The developed method enables the synthesis of large-pore and ultra-large-pore zeolites not easily obtained conventionally.
• NUD-19's unique structure and porosity make it a promising material for catalysis, adsorption, and separation.
• This strategy offers a new pathway for designing advanced zeolite materials.