Irreversible deformation of hyper-crosslinked polymers after hydrogen adsorption

Area of Science:

• Materials Science
• Polymer Chemistry
• Chemical Engineering

Background:

• Hyper-crosslinked polymers (HCPs) are advanced porous materials.
• Graphene oxide (GO) is explored as a composite additive.
• Hydrogen storage is a critical area of research.

Purpose of the Study:

• Synthesize HCPs using various precursors and a crosslinker.
• Investigate the impact of graphene oxide (GO) on HCP properties.
• Evaluate the hydrogen adsorption capacity of HCPs and HCP-GO composites.

Main Methods:

• Friedel-Crafts reaction for HCP synthesis.
• BET analysis for surface area determination.
• High-pressure hydrogen adsorption measurements at 77 K.

Main Results:

• HCPs exhibited high BET surface areas (590-1120 m²g⁻¹).
• Benzene-derived HCP (B1FeM2) and its GO composite showed highest surface areas.
• Maximum H₂ excess uptake of 2.1 wt% (B1FeM2) and 2.0 wt% (B1FeM2-GO) at 4 MPa and 77 K.
• GO addition increased density but reduced surface area.
• Irreversible deformation observed above 4 MPa.

Conclusions:

• HCPs and HCP-GO composites show potential for hydrogen storage at moderate pressures.
• Material density is crucial for volumetric hydrogen storage capacity.
• High-pressure stability is a limitation for these materials in hydrogen adsorption applications.