Materials designed by a Florida State University professor could enable more efficient storage of hydrogen fuel for cars.

Jose Mendoza-Cortes, a researcher at the university’s High-Performance Materials Institute (HPMI), describes the materials in the Journal of the American Chemical Society.

Hydrogen filling station in Iceland. Credit: Wikimedia CommonsThe problem Mendoza-Cortes addresses is the necessity to pressurize hydrogen to make it usable for cars. The existing pressurization process, physisorption, produces a usable fuel. But the process is neither efficient nor economically viable. His approach was to design materials that could bond with hydrogen and then use the materials in a hydrogen-fueled car’s tank.

By binding hydrogen to the device placed in the fuel tank, Mendoza-Cortes could pack more hydrogen into a tank and store it at lower pressures. He designed 270 different compounds of transition metals – compounds using cobalt, iron, or nickel – using computer simulation.

Thirty novel covalent organic frameworks (COFs) were tested for hydrogen uptake using quantum mechanics (QM)-based force fields and grand canonical Monte Carlo (GCMC) simulations. The testing indicated that these new compounds required 37 grams per liter of hydrogen at 200 bar pressure and room temperature. Current technology requires 700 bar and 298 degrees Kelvin to store the equivalent amount of hydrogen. Another advantage of these “sticky” storage materials is that the fuel tank will never be completely empty.