Exceptional H2 saturation uptake in microporous metal-organic frameworks

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Microporous materials, such as metal-organic frameworks (MOFs), are promising for gas storage applications.
• Understanding hydrogen (H2) uptake mechanisms and capacities in MOFs is crucial for developing efficient storage solutions.

Purpose of the Study:

• To quantify the saturation H2 uptake in a series of microporous MOFs at cryogenic temperatures (77 K).
• To investigate the correlation between MOF properties, such as surface area, and H2 storage capacity.
• To assess the feasibility of volumetric H2 storage in highly porous MOF materials.

Main Methods:

• Experimental measurement of H2 uptake at 77 K for a series of MOFs.
• Determination of saturation pressures, ranging from 25 to 80 bar.
• Analysis of gravimetric and volumetric H2 uptake capacities.

Main Results:

• MOF-177 exhibited the highest gravimetric H2 uptake at 7.5 wt %.
• IRMOF-20 demonstrated the highest volumetric H2 uptake, reaching 34 g/L.
• A strong correlation was observed between the surface area of MOFs and their maximum H2 storage capacity.

Conclusions:

• Maximum H2 storage capacity in MOFs is significantly influenced by their surface area.
• Feasible volumetric H2 uptakes can be achieved in highly porous MOF materials, indicating their potential for practical hydrogen storage.
• These findings support the development of MOFs for advanced hydrogen storage technologies.