A novel catalytic route for hydrogenation-dehydrogenation of 2LiH + MgB2: Via in situ formed core-shell LixTiO2 nanoparticles

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 LixTiO2 nanoparticles during milling and upon heating. These nanoparticles markedly enhance the hydrogen...

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Bibliographic Details
Authors: Puszkiel, Julián Atilio, Castro Riglos, Maria Victoria, Ramallo Lopez, Jose Martin, Mizrahi, Martin Daniel, Karimi, F., Santoru, Antonio, Hoell, Armin, Gennari, Fabiana Cristina, Arneodo Larochette, Pierre Paul, Pistidda, Claudio, Klassen, Thomas, Bellosta Von Colbe, J.M., Dornheim, M.
Format: article
Status:Published version
Publication Date:2017
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/125958
Online Access:http://hdl.handle.net/11336/125958
Access Level:Open access
Keyword:HYDROGEN STOREGE
CORESHELL NANOPARTICLES
TiO2
XANES
https://purl.org/becyt/ford/2.5
https://purl.org/becyt/ford/2
Description
Summary: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 LixTiO2 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 LixTiO2 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 LixTiO2 nanoparticles accelerates the one-dimensional interface-controlled mechanism during hydrogenation owing to the high Li+ mobility through the LixTiO2 lattice. Upon dehydrogenation, the in situ formed core-shell LixTiO2 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.

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