Thermodynamics of hydrogen storage: LOHC system 1-alkyl-indole/octahydro-1-alkyl-indole

The environmental advantages of the hydrogen economy are obvious, but the limiting factor in its development is finding an optimal storage system with high gravimetric and volumetric hydrogen capacities. The most effi-cient technology for storing and consequently using hydrogen is that with organic compounds that are able to enrich hydrogen by forming bonds with the hydrogen. In this study, we considered 1-alkyl-indoles as suitable LOHC systems because of their high thermal stability and high boiling points. The thermochemical studies of these compounds were performed, including vapour pressure measurements and combustion calorimetry. The experimental data obtained are compared with the results of theoretical quantum chemical methods. In addition, a thermodynamic analysis of the hydrogenation/dehydrogenation of the LOHC systems based on 1-alkyl-indoles was performed.