Résumé:

In recent years, a great emphasis has been placed on replacing fossil fuels with clean, re-newable energy for use in vehicles. One potential solution is the use of hydrogen gas as a fuel source to power a fuel cell. For vehicular use, the US Department of Energy (DOE) has identified three major challenges to implementing a hydrogen-powered solution: (i) hydrogen production costs must be substantially lowered, (ii) fuel-cell costs should be reduced and (iii) hydrogen storage systems capable of delivering a driving range of hundreds of kilometers, without major detrimental effects to vehicle cost, safety, or cargo capacity must be developed. Hydrogen adsorption in carbon porous structures is a fundamental problem for these applications. Although many porous carbons exist in the nature, or have been prepared during recent decades, most of them show hydrogen storage capacity that is too low for practical applications.It has been shown that it is not possible to increase hydrogen storage capacity only by modification of pore geometry without simultaneous increase of the material specific surface. So, we have conceived graphene-based structures with high surfaces and analyzed their adsorption properties. These new models of hypothetical activated carbons have low density architecture required for effective storage media in mobile applications. We call them Open Carbon Frameworks (OCF). Theoretically they may have the specific surfaces exceeding 6000 m2/g. The question arises: Is it possible to prepare a porous carbon structure that will have properties required for hydrogen adsorption? Our discussion is focused on hypothetical model materials that have not been yet practically synthesized. It shows a vision and one possible way of searching for new porous carbon-based structures with properties required for storage applications. From such perspective it is interesting to discuss also the recent exceptional predictions of enhanced storage capacity of Covalent Organic Frameworks (COF’s) materials and Porous Aromatic Frameworks (PAF’s).