Many methods have been proposed for efficient storage of molecular hydrogen for fuel cell applications. However, despite intense research efforts, so far, the industrial parameters of 6.5% mass ratio and 62 kg/m3 volume density are still questionable though the results are obtained by either experimentally or via theoretical simulations on reversible model systems. Carbon-based materials, have always been regarded as the most attractive physisorption substrates for the storage of hydrogen. Theoretical and experimental studies on various model carbon systems, however, failed to reach the elusive goal. In this work, it is shown that insufficiently accurate carbon - hydrogen diatomic interaction potentials, together with the neglect and incomplete treatment of the quantum effects in previous theoretical investigations, led to misleading conclusions for the absorption capacities of different carbon materials. A proper account of the contribution of quantum effects to the free energy and the equilibrium constant for hydrogen adsorption suggest that the industry specifications can be approached in a graphite-based physisorption system. The theoretical prediction can be realised by optimising the topology, the cavity shape and the accessible surface of the carbon structures.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:24876 |
| Date | 23 October 2007 |
| Creators | Zhechkov, Lyuben |
| Contributors | Seifert, Gotthard, Mineva, Tzonka, Kirchner, Barbara |
| Publisher | Technische Universität Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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