Last month at the International Symposium on Materials Issues in a Hydrogen Economy, held in Richmond, Virginia a new development in room temperature adsorption of large amounts of hydrogen (14% by weight!) was announced. The work was presented by Bellave Shivaram and Adam Phillips, of the University of Virginia. Absorbing hydrogen at room temperature at these levels is a significant development. What remains to be worked out is if the substrate can be induced to easily give it back and if the catalyst (sorbent) can be recycled. http://www.rsc.org/chemistryworld/News/2007/November/16110701.asp The attached graphic shows how the complex is believed to function. The (green) hydrogen molecules are shown as ligands to (red) titanium atoms coupled to an (yellow) ethylene molecule.