Hydrogen-Storage Materials Based on Imidazolium Ionic Liquids

Abstract

Simple 1-alkyl(aryl)-3-methylimidazolium N-bis(trifluoromethanesulfonyl)imidate salts that possess very low vapor pressure, high density, and thermal stability and are not inflammable can add reversibly 6-12 hydrogen atoms in the presence of classical Pd/C or Ir 0 nanoparticle catalysts and can be used as alternative materials for on-board hydrogen-storage devices. These salts can hold up to 30 g L -1 of hydrogen at atmospheric pressure, which is twice that compressed hydrogen gas can attain at 350 atm.

Hydrogen Storage Using Ionic Liquid Media

“…Another attempt to incorporate a hydrogen carrier into an IL was performed by attaching a side-chain containing a cyclohexyl moiety to an imidazolium cation [58]. Here, Pd/C was used at elevated temperatures during the cyclohexyl dehydrogenation and rehydrogenation process (Scheme 3).…”

Application of Ionic Liquids in Hydrogen Storage Systems

“…(Stracke et al, 2007) This group used commercial palladium on charcoal catalyst and rather harsh conditions in the dehydrogenation/hydrogenation cycles. Despite the theoretical storage capacity of this system being insignificant, this was the first report of an IL being employed as hydrogen storage material.…”

Advancement in Molecular Hydrogen Storage Systems

“…Initial attempts using an IL containing a cyclohexyl moiety as hydrogen carrier were reported by Dupont and co-workers. [15] The theoretical capacity of Me-GBH of 9.0 wt % is substantially below that of the wellexplored AB (19.6 wt %). [13] However, the liquid state of Me-GBH under standard-conditions makes this material interesting for future applications and worth investigating further.…”