Hydrogen storage materials act like sponges, capable of filling up with certain gases and later releasing them. The challenge is developing materials that hold useful amounts of hydrogen, and that store and release the hydrogen easily.
Today’s hydrogen storage materials hold 2 to 4 percent of their weight in hydrogen, short of the 6.5 percent Department of Energy goal for using hydrogen as automobile fuel.
Researchers from the University of Michigan, the University of California at Santa Barbara, the University of South Florida and Arizona State University have discovered a new class of materials, dubbed metal-organic frameworks, that are relatively inexpensive to make and have the potential to reach the 6.5 percent mark.
The discovery promises to remove the principal stumbling block to hydrogen-powered cars, and the method could be ready for production use within five years.
Current hydrogen storage systems chemically bind powdered metal hydrides to hydrogen at high temperatures. In November, researchers in Singapore developed a metal material that holds more than 11 percent of its weight in hydrogen, but requires high temperatures and pressures. Researchers are also exploring carbon-based approaches, including carbon nanotubes, but these require very low temperatures.