Tag Archives: solid-state nmr

Storage properties of the Li-N-H system

hydrogen_energy“Role of aluminum chloride on the reversible hydrogen storage properties of the Li-N-H system”

Fernández, L.; Garroni, S.; Larochette, P.; Nolis, P.; Mulas, G.; Enzo, S.; Baró, M.D.; Gennari, F. International Journal of Hydrogen Energy, IN PRESS 2015 doi:10.1016/j.ijhydene.2015.08.030

 In order to understand the role of AlCl3 addition on the Li–N–H system, we have systematically investigated the hydrogen sorption kinetics and the reactions between LiNH2–LiH and AlCl3 additive with a multitechnique approach involving differential scanning calorimetry (DSC), hydrogen volumetric measurements, X-ray powder diffraction (XRPD), Fourier transform infrared analysis (FTIR) and solid-state nuclear magnetic resonance (NMR). Continue reading Storage properties of the Li-N-H system

Confining light metal hydrides in micro- or mesoporous scaffolds

JournalMaterialResearch“Unusual Oxidation Behavior of Light Metal Hydride by Tetrahydrofurane Solvent Molecules Confined in Ordered
Mesoporous Carbon” Klose, M.; Lindemann, I.; Minella, C.; Pinkert, K.; Zier, M.; Giebeler, L.; Nolis, P.; Baro, M.; Oswald, S.; Gutfleisch, O.; Ehrenberg, H.; Eckert, J. Journal Of Materials Research, 2014, 29, 55-63 DOI:10.1557/jmr.2013.199

Confining light metal hydrides in micro- or mesoporous scaffolds is considered to be a promising way to overcome the existing challenges for these materials, e.g. their application in hydrogen storage. Different techniques exist which allow us to homogeneously fill pores of a host matrix with the respective hydride, thus yielding well defined composite materials. Continue reading Confining light metal hydrides in micro- or mesoporous scaffolds

Structural evolution upon decomposition of the LiAlH4+LiBH4 system

jalloysStructural evolution upon decomposition of the LiAlH4+LiBH4 system. S. Soru, A. Taras, C. Pistiddb, C. Milanese, C. Bonatto Minella, E. Masolo, P. Nolis, M. D. Baró, A. Marinic, M. Tolkiehn,M. Dornheim, S. Enzo, G. Mulas, S. Garroni. Journal of Alloys and Compounds 2014, in press. DOI: 10.1016/j.jallcom.2013.12.027

In the present work we focus the attention on the phase structural transformations occurring upon the desorption process of the LiBH4 + LiAlH4 system. Continue reading Structural evolution upon decomposition of the LiAlH4+LiBH4 system

NaAlH4 confined in Ordered Mesoporous Carbon

hydrogen_energyNaAlH4 confined in Ordered Mesoporous Carbon

Bonatto, C.; Lindemann, I.; Nolis, P.; KieBling, A.; Baró, M. D.; Klose, M.; Giebler, L.; Rellinghaus, B.; Eckert, J.; Schultz, L.; Gutfleisch, O.

In this paper we performed a comprehensive investigation of the structural and sorption properties of a 40 wt. % NaAlH4 confined in a ordered mesoporous carbon (OMC, i.e. CMK-3) by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), 23Na{1H} and 27Al{1H} solid-state magic angle spinning-nuclear magnetic resonance (MAS-NMR).

This study evidences a remarkable improvement of the sorption kinetics of NaAlH4 due to its existence in nanometer size within the OMC. The pressure composition isotherm (PCI) analysis (for the re-absorption step) of the nanoconfined NaAlH4 would suggest an alteration of its equilibrium thermodynamic properties.

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Additives on the Ca(BH) system

jpccck_v116i051.indd“Chemical State, Distribution and Role of Ti- and Nb-Based Additives on the Ca(BH4)2 System” by Christian Bonatto Minella, Eva Pellicer, Emma Rossinyol, Fahim Karini, Claudio Pistidda,Sebastiano Garroni, Chiara Milanese, Pau Nolis, Maria Dolors Baró, Oliver Gutfleisch, Klaus Pranzas, Andreas Schreyer, Thomas Klassen, Rüdiger Bormann and Martin Dornheim. The Journal of Physical Chemistry C. 117:4394-4403 (2013). DOI: 10.1021/jp3116275

Light metal tetrahydroborates are regarded as promising materials for solid state hydrogen storage. Due to both a high gravimetric hydrogen capacity of 11.5 wt. % and an ideal de-hydrogenation enthalpy of 32 kJ mol-1 H2, Ca(BH4)2 is considered to be one of the most interesting compounds in this class of materials. In this work, a comprehensive investigation of the effect of different selected additives (TiF4, NbF5, Ti-isopropoxide and CaF2) on the reversible hydrogenation reaction of calcium borohydride is presented combining different investigation techniques.  Continue reading Additives on the Ca(BH) system

Ca(BH4)2 + MgH2: Desorption Reaction

jpccck_v117i005.indd“Ca(BH4)2 + MgH2: Desorption Reaction and Role of Mg on its Reversibility” by Christian Bonatto Minella, Claudio Pistidda, Sebastiano Garroni, Pau Nolis, Maria Dolors Baró, Oliver Gutfleisch, Thomas Klassen, Rüdiger Bormann, and Martin Dornheim. The Journal of Physical Chemistry C. 117:3846-3852 (2013). DOI: 10.1021/jp312271s

The Ca(BH4)2-MgH2 composite system represents a promising candidate for mobile hydrogen storage due to a 10.5 wt. % theoretical hydrogen storage capacity and an estimated equilibrium temperature lower than 160 °C. For this system, the reversibility was achieved without further addition of additives. Continue reading Ca(BH4)2 + MgH2: Desorption Reaction

Organic composition in soil studied by solid state NMR

Changes in soil bacterial community: diversity, composition and function triggered by drought-induced gap succession preceded changes in soil C stocks and quality ” Curiel-Yuste J., Barba J., Fernandez-Gonzalez A.J., Fernandez-Lopez M., Mattana S., Martinez-Vilalta J., Pau Nolis, Lloret F. Ecology and Evolution. Accepted 2012.

We investigated soil bacterial taxonomic composition, soil respiration and soil organic matter quantity and quality in a mixed Mediterranean forest where the Scots pine (Pinus sylvestris) population is affected by climatic drought-induced die-off, and replaced by Holm-oak (Quercus ilex) populations as the dominant tree species. Continue reading Organic composition in soil studied by solid state NMR

Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4 + MgH2 system

“Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4+ MgH2 system”, by Sebastiano Garroni, Chiara Milanese, Daphiny Pottmaier, Gabriele Mulas, Pau Nolis, Alessandro Girella, Riccarda Caputo, David Olid-Britos, Francesc Teixidor, Marcello Baricco, Amedeo Marini, Santiago Suriñach, and Maria Dolores Baró. The Journal of Physical Chemistry C, Volume 115, Pages 16664-16671, July 2011. DOI: 10.1021/jp202341j

In the present work we report the desorption pathway of the 2NaBH4 + MgH2 system. Ex-situ X-ray powder diffraction (XRPD) and solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) measurements have been performed on samples heat-treated up to 450°C for different times. Ex-situ X-ray powder diffraction experiments conducted on fully desorbed samples allowed to identify nanocrystalline MgB2 and metallic Na as dehydrogenation products. Continue reading Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4 + MgH2 system

Activation of the reactive hydride composite 2NaBH4 + MgH2

“Activation of the reactive hydride composite 2NaBH4 + MgH2” by C. Pistidda, G. Barkhordarian, A. Rzeszutek, S. Garroni, C. Bonatto Minella, M.D. Baró, P. Nolis, Rüdiger Bormann, T. Klassena and M. Dornhei. Scripta Materialia, Volume 64, Issue 11, June 2011, Pages 1035-1038. DOI: 10.1016/j.scriptamat.2011.02.017

A novel method to enhance the reaction kinetics of the reactive hydride composite 2NaBH4 + MgH2 is described. It has been discovered that short-term exposure to a moist atmosphere has a very beneficial effect on the desorption reaction of the 2NaBH4 + MgH2 mixture. By this procedure it is possible to achieve, after drying, both faster desorption kinetics and greater amounts of released hydrogen compared to ball-milled material without further treatment.