US Patent 7118611 - Dual Nanoparticles for Hydrogen Storage

http://www.freepatentsonline.com/7118611.pdf

Hydrogen fuel cells require materials capable of storing hydrogen efficiently. Fullerenes and carbon nanotubes have already been experimented with as candidate materials for such storage and this patent exploits the high surface to volume ratio of nanoparticle mixtures to achieve hydrogen storage. Claim 1 reads:

1. A material for storing hydrogen as a hydride, wherein the material comprises: a physical mixture of a plurality of non-graphitic first nanoparticles capable of storing hydrogen as a hydride, having an average diameter of about 2 nm to about 200 nm; and a plurality of second nanoparticles, wherein the second nanoparticles are essentially all different from the first nanoparticles by at least one member selected from the group consisting of chemistry structure, average shape, average size, crystallinity, coating, aggregation, and combinations thereof, the second nanoparticle has an average critical dimension of about 200 to about 950 nanometers, and the second particle is capable of storing hydrogen as a hydride.