A team of chemists from the University of Hong Kong, Northwestern University, and Duke University has developed a supramolecular material capable of compressing hydrogen for storage without being too heavy. Their study, published in Nature Chemistry, demonstrates the use of porous organic crystals for hydrogen storage.

Hydrogen has long been touted as a clean energy source but remains underutilized due to storage challenges—it occupies much more space than gasoline. Researchers worldwide have been working on better compression techniques to address this issue.

In this study, the team aimed to meet the U.S. Department of Energy's targets for hydrogen storage: the first, storing at least 50 g of hydrogen per liter of material, and the second, ensuring that the weight of hydrogen stored should be 6.5% or more of the total material weight.

Previous efforts have failed to meet both targets simultaneously, but the researchers claim their material achieves these goals. It consists of organic molecules arranged in a robust honeycomb-shaped crystal structure, with pores optimized for hydrogen molecules. The hydrogen bonds to the crystals, enabling efficient storage.

This interlinked structure allows for tighter and more stable hydrogen storage while reducing the porosity seen in other materials. Tests revealed the material could store 53.7 g of hydrogen per liter, with hydrogen accounting for 9.3% of the system's overall weight. However, the system requires cryogenic cooling, which could be bulky and expensive in commercial applications.

More information: Ruihua Zhang et al, Balancing volumetric and gravimetric capacity for hydrogen in supramolecular crystals, Nature Chemistry (2024). DOI: 10.1038/s41557-024-01622-w

Image Credit: Nature Chemistry (2024). DOI: 10.1038/s41557-024-01622-w

Source: Physics.org