Metal-Organic Frameworks and Composites for Ammonia Capture

Area of Science:

• Materials Science
• Chemical Engineering
• Sustainable Chemistry

Background:

• The Haber-Bosch process drives ammonia demand but faces storage challenges due to ammonia's properties.
• Metal-organic frameworks (MOFs) offer high porosity and tunable functionality for ammonia adsorption.
• MOF stability upon ammonia exposure remains a critical research obstacle.

Purpose of the Study:

• To review recent advancements in MOFs for ammonia adsorption and storage.
• To highlight key mechanisms enhancing ammonia uptake and stability in MOFs.
• To discuss future challenges and prospects for MOF-based ammonia capture.

Main Methods:

• Focus on MOF synthesis and post-synthetic modification strategies.
• Investigate adsorption mechanisms involving open metal sites, µ-OH groups, and defects.
• Analyze functional surface modifications and composite material approaches.

Main Results:

• Unsaturated metal sites and Brønsted acidic µ-OH groups enhance ammonia binding.
• Defect engineering and functional modifications increase ammonia adsorption capacity.
• MOF composites exhibit superior ammonia capture performance via synergistic effects.

Conclusions:

• MOFs present a viable alternative for ammonia storage and transport.
• Continued research into stability and scalable synthesis is crucial.
• Functionalization and composite strategies offer promising pathways for improved MOF performance.