A study published recently in the journal Physical Review Letters highlights the discovery of a new hydrogen clathrate hydrate that could improve the storage and transportation of hydrogen fuels. The newly described hydrogen hydrate forms at room temperature and low pressures, reports the team of chemists hailing from the United States, China, and Russia.
The collaboration of scientists from the Carnegie Institution of Washington (USA) and the Institute of Solid State Physics in Hefei (China) was led by Skoltech professor Artem R. Oganov and Alexander F. Goncharov. The team explains that hydrogen hydrates’ crystal structure is largely influenced by pressure: at low pressures, the hydrates have large cavities that hold hydrogen molecules, but as pressure raises, the hydrates’ crystal structure becomes denser with more and more hydrogen molecules.
Because hydrogen stored in its natural form poses an explosion risk, scientists are on the hunt for cost-effective ways to store hydrogen. Some think hydrates could offer a solution. "This is not the first time we turn to hydrogen hydrates,” says Oganov.
“In our previous research, we predicted a novel hydrogen hydrate with 2 hydrogen molecules per water molecule. Unfortunately, this exceptional hydrate can only exist at pressures above 380,000 atmospheres, which is easy to achieve in the lab but is hardly usable in practical applications. Our new paper describes hydrates that contain less hydrogen but can exist at much lower pressures.”
The hydrates that the study speaks of are unique in that they have 3 water molecules per hydrogen molecule. Not unlike the known proton-ordered C1 hydrate and its properties, this new hydrate is capable of proton disorder at room temperatures.