High Surface Area Nanoporous Polymers for Reversible Hydrogen Storage

Hydrogen adsorption using a series of nanoporous synthetic polymers has been studied. Promising results were obtained during the screening of commercially available porous polymer beads; of the polymers considered, hypercrosslinked Hypersol-Macronet MN200 resin exhibited the highest adsorption capacity for hydrogen. This initial success triggered the development of our own high surface area hypercrosslinked materials. Subjecting gel-type and macroporous vinylbenzyl chloride-based precursors swollen in dichloroethane to a Friedel−Crafts reaction catalyzed by iron trichloride afforded beads with surface areas of 1 930 and 1 300 m2/g, respectively, as calculated using the BET equation. The former polymer reversibly stores up to 1.5 wt % H2 at a pressure of 0.12 MPa and a temperature of 77.3 K. The initial heat of adsorption of hydrogen molecules onto this polymer is 6.6 kJ/mol.