Hydrogen 'bottleneck' banished

Hydrogen-powered cars that do not pollute the environment are a step closer thanks to a new discovery which promises to solve the main problem holding back the technology.

Petrol stations could be offering hydrogen along with unleaded sooner than you think.

Whilst hydrogen is thought to be an ideal fuel for vehicles, producing only water on combustion, its widespread use has been limited by the lack of a safe, efficient system for onboard storage.

Now scientists have invented a material which stores and releases hydrogen at room temperature, at the flick of a switch, and promises to help make hydrogen power a viable clean technology for the future.

“The problem of how to store hydrogen has been a major bottleneck in the development of the hydrogen power technology,” said Dr Andrew Weller from the Department of Chemistry at the University of Bath.  

“Hydrogen has a low density and it only condenses into liquid form at -252°C so it is difficult to use conventional storage systems such as high-pressure gas containers which would need steel walls at least three inches thick, making them too heavy and too large for cars.”

The team constructed an organo-metallic compound containing six rhodium atoms and 12 hydrogen atoms and found that the material would absorb two molecules of hydrogen at room temperature and atmospheric pressure – and would release the molecules when a small electric current was applied to the material.

“The new material absorbs the hydrogen into its structure and literally bristles with molecules of the gas. At the flick of a switch it rejects the hydrogen, allowing us to turn the supply of the gas on and off as we wish,” said Dr Weller.

The researchers are now looking at ways of printing the material onto sheets that could be stacked together and encased to form a storage tank.