New Pathway to Forming Hydrogen Storage Compounds

Tuesday, November 24 2009

Scientists at the Carnegie Institution for Science have found that high pressure can be used to make a unique hydrogen-storage material. The researchers found that the normally unreactive, noble gas xenon combines with molecular hydrogen under pressure to form a previously unknown solid with unusual bonding chemistry.

The experiments at the Carnegie Institution are the first time these elements have been combined to form a stable compound. The discovery debuts a new family of materials, which could boost new hydrogen technologies.

Xenon has some interesting properties, including its use as an anesthesia, its ability to preserve biological tissues, and its employment in lighting. Xenon is a noble gas, which means that it does not typically react with other elements.

Maddury Somayazulu, a research scientist at Carnegie’s Geophysical Laboratory, explained: “Elements change their configuration when placed under pressure, sort of like passengers readjusting themselves as the elevator becomes full. We subjected a series of gas mixtures of xenon in combination with hydrogen to high pressures in a diamond anvil cell. At about 41,000 times the pressure at sea level (1 atmosphere), the atoms became arranged in a lattice structure dominated by hydrogen, but interspersed with layers of loosely bonded xenon pairs. When we increased pressure, like tuning a radio, the distances between the xenon pairs changed–the distances contracted to those observed in dense metallic xenon.”