Crystal Orientation and Defect Mapping in Electron-Beam-Sensitive Zeolites with Near-Axis Transmission Kikuchi...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Porous materials like zeolites are essential for catalysis, energy conversion, and environmental remediation.
• Understanding structural heterogeneity in zeolites is critical for optimizing their synthesis, framework intergrowths, and catalytic performance.
• Existing methods for phase identification and spatial mapping in zeolites lack the necessary resolution or throughput.

Purpose of the Study:

• To develop a high-throughput approach for high-resolution phase identification and spatial mapping of zeolites.
• To enable direct visualization of structural heterogeneity and intergrowth features in electron-beam-sensitive zeolites.
• To bridge the resolution and throughput gap between X-ray diffraction and transmission electron microscopy.

Main Methods:

• Utilized near-axis transmission Kikuchi diffraction (TKD) in a scanning electron microscope (SEM).
• Applied the method to electron-beam-sensitive zeolites, including ZSM-5 and Zeolite A.
• Combined nanoscale mapping with statistical sampling for high-throughput analysis.

Main Results:

• Achieved high phase and spatial resolution for electron-beam-sensitive zeolites.
• Successfully mapped Zeolite A for the first time using this technique.
• Enabled direct visualization of intergrowth features impacting catalytic and adsorption behavior.

Conclusions:

• The developed near-axis TKD method provides a powerful tool for characterizing structural heterogeneity in zeolites.
• This technique bridges the gap between ensemble-averaged and high-resolution microscopy methods.
• The approach is suitable for machine-learning pipelines and can be extended to other beam-sensitive porous materials.