Small Pore Aluminosilicate EMM-37: Synthesis and Structure Determination Using Continuous Rotation Electron...

Area of Science:

• Materials Science
• Crystallography
• Chemistry

Background:

• Zeolites are crystalline aluminosilicates with diverse industrial applications.
• Developing new zeolites with unique pore structures is crucial for advanced catalysis and separation processes.
• Structure determination of novel materials, especially at the nanoscale, presents significant challenges.

Purpose of the Study:

• To synthesize and characterize a new aluminosilicate zeolite with a 3D small pore channel system.
• To elucidate the crystal structure of the as-made and calcined forms of the new zeolite.
• To demonstrate the utility of continuous rotation electron diffraction (cRED) for complex nanosized crystal structure determination.

Main Methods:

• Synthesis of a novel aluminosilicate zeolite (EMM-37) using a diquaternary ammonium molecule as a structure directing agent (SDA) and metakaolin as the aluminum source.
• Structure solution and refinement of both as-made and calcined EMM-37 using continuous rotation electron diffraction (cRED) data.
• Utilizing cRED for collecting 3D electron diffraction data from submicron- and nanosized crystals.

Main Results:

• Successful synthesis of a new aluminosilicate zeolite, EMM-37, possessing a 3D small pore channel system.
• The crystal structures of both as-made and calcined EMM-37 were successfully solved and refined.
• Demonstrated that cRED is effective for determining complex structures, even in low symmetry (P1̅), from nanosized crystals.

Conclusions:

• EMM-37 represents a new zeolite framework with potential applications in areas requiring small pore systems.
• Continuous rotation electron diffraction (cRED) is a powerful and viable technique for the structural analysis of novel, nanosized crystalline materials.
• The successful structure determination highlights advancements in crystallographic methods for materials discovery.