1. Hydrogen storage properties of eutectic metal borohydrides melt-infiltrated into porous Al scaffolds.
- Author
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Sofianos, M. Veronica, Chaudhary, Anna-Lisa, Paskevicius, Mark, Sheppard, Drew A., Humphries, Terry D., Dornheim, Martin, and Buckley, Craig E.
- Subjects
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HYDROGEN storage , *EUTECTICS , *HYDRIDES , *MELTING , *POROUS materials , *ALUMINUM - Abstract
Abstract Porous Al scaffolds were synthesised and melt-infiltrated with various eutectic metal borohydride mixtures (0.725LiBH 4 -0.275KBH 4, 0.68NaBH 4 -0.32KBH 4, 0.4NaBH 4 -0.6 Mg(BH 4) 2) to simultaneously act as both a confining framework and a reactive destabilising agent for H 2 release. The scaffolds were synthesised by sintering a pellet of NaAlH 4 /2 mol%TiCl 3 at 450 °C under dynamic vacuum. During the sintering process the sodium alanate (NaAlH 4) decomposed to Al metal. The vacuum applied at elevated temperature promoted the Na metal to vaporise and be extruded from the pellet. The pores of the resulting Al scaffold were created during removal of the H 2 and the Na from the body of the NaAlH 4 /2 mol%TiCl 3 pellet. According to the morphological observations carried out by a Scanning Electron Microscope (SEM), melt-infiltrated eutectic mixtures of metal borohydrides were highly dispersed into the porous scaffolds. Temperature Programmed Desorption (TPD) experiments, revealed that the melt-infiltrated samples exhibited faster H 2 desorption kinetics in comparison to bulk samples, with onset temperatures (T des) lower than the bulk by 150–250 °C. The as-synthesised porous Al scaffolds acted as a reactive containment vessel for these eutectic mixtures that simultaneously nanoconfined and destabilised the mixtures. Highlights • Porous scaffolds were fabricated by sintering a NaAlH 4 /2 mol%TiCl 3 pellet at 450 °C. • The pores formed an open network with thin interconnecting walls. • The porous Al scaffolds destabilised the infiltrated eutectic mixtures. • All melt-infiltrated samples started desorbing H 2 150–250 °C lower than the bulk. • The melt-infiltrated samples showed faster reaction kinetics to the bulk. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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