When simple gases meet water at ambient conditions, little happens. But at high pressure and low temperature, hydrogen-bond networks within water can build polyhedron cages around guest molecules like methane, nitrogen, or argon to form hydrogen clathrates. Wendy Mao (University of Chicago) and her father Ho-kwang Mao (Carnegie Institution of Washington) have developed a way to store large concentrations of hydrogen within such clathrate cages. Using a diamond anvil cell, they compressed hydrogen gas and water to 250 MPa and noticed the mixture nucleate at about 250 K to form H2(H2O)2, a clathrate cage with enclosed hydrogen gas clusters. Provided that it’s stored at temperatures below about 140 K, the compound remains stable even when the pressure drops to ambient levels. At warmer temperatures, the clathrate decomposes to release its stored gas. The density of hydrogen stored within the hydrate is 50 g/L, significantly...
Skip Nav Destination
Article navigation
1 March 2004