A novel catalytic route for hydrogenation–dehydrogenation of 2LiH + MgB2via in situ formed core–shell LixTiO2 nanoparticles. Issue 25 (7th June 2017)

• Record Type: Journal Article
• Authors: Puszkiel, J. A.; Castro Riglos, M. V.; Ramallo-López, J. M.; Mizrahi, M.; Karimi, F.; Santoru, A.; Hoell, A.; Gennari, F. C.; Larochette, P. Arneodo; Pistidda, C.; Klassen, T.; Bellosta von Colbe, J. M.; Dornheim, M.
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 25(2017)
• Page Start: 12922
• Page End: 12933
• Publication Date: 2017-06-07
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta03117c
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Aiming to improve the hydrogen storage properties of 2LiH + MgB2 (Li-RHC), the effect of the in situ formed and low cost Li x TiO2 is investigated. Abstract : Aiming to improve the hydrogen storage properties of 2LiH + MgB2 (Li-RHC), the effect of TiO2 addition to Li-RHC is investigated. The presence of TiO2 leads to the in situ formation of core–shell Li x TiO2 nanoparticles during milling and upon heating. These nanoparticles markedly enhance the hydrogen storage properties of Li-RHC. Throughout hydrogenation–dehydrogenation cycling at 400 °C a 1 mol% TiO2 doped Li-RHC material shows sustainable hydrogen capacity of ∼10 wt% and short hydrogenation and dehydrogenation times of just 25 and 50 minutes, respectively. The in situ formed core–shell Li x TiO2 nanoparticles confer proper microstructural refinement to the Li-RHC, thus preventing the material's agglomeration upon cycling. An analysis of the kinetic mechanisms shows that the presence of the core–shell Li x TiO2 nanoparticles accelerates the one-dimensional interface-controlled mechanism during hydrogenation owing to the high Li + mobility through the Li x TiO2 lattice. Upon dehydrogenation, the in situ formed core–shell Li x TiO2 nanoparticles do not modify the dehydrogenation thermodynamic properties of the Li-RHC itself. A new approach by the combination of two kinetic models evidences that the activation energy of both MgH2 decomposition and MgB2 formation is reduced. These improvements are due to a novel catalytic mechanism via Li + source/sink reversible reactions.