Hydrogen storage properties of rare earth (RE) borohydrides (RE = La, Er) in composite mixtures with LiBH4 and LiH
| Autor: | Magnus H. Sørby, M. D. Riktor, Bjørn C. Hauback, Michael Heere, Christoph Frommen |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Hydrogen
Mechanical Engineering Thermal decomposition Metals and Alloys chemistry.chemical_element Mineralogy Atmospheric temperature range Borohydride Decomposition Chemical reaction chemistry.chemical_compound Hydrogen storage chemistry Mechanics of Materials Desorption Materials Chemistry Physical chemistry |
| Zdroj: | Journal of Alloys and Compounds S155-S159 |
| Popis: | Mixtures of 6LiBH 4 –RECl 3 –3LiH (RE = La, Er) have been produced by mechanochemical milling and their structure, thermal decomposition and reversibility have been studied. Hydrogen desorption starts around 300 °C in both composites. Heating to 400 °C yields LaB 6 , ErB 4 and REH 2+ δ as major decomposition products. LiBH 4 is destabilized by REH 2+ δ formed through decomposition of the parent borohydrides LiLa(BH 4 ) 3 Cl and Er(BH 4 ) 3 , respectively, and its hydrogen release temperature is reduced by 100 °C as compared to pure ball-milled LiBH 4 . The lanthanum-containing composite releases 4.2 wt.% H between 300 and 350 °C and shows a limited reversibility of ∼20% (340 °C, 10 MPa) probably due to hydrogen uptake by some amorphous boron-containing phases. For 6LiBH 4 –ErCl 3 –3LiH about 3 wt.% H is evolved up to 400 °C. Desorption against 0.5 MPa backpressure results in an increased reversibility (∼80%) as compared to vacuum (∼66%). Rehydrogenation (340 °C, 10 MPa) shows the formation of ErH 3 and LiBH 4 at drastically reduced conditions compared to pure LiBH 4 (>400 °C, >10 MPa). |
| Databáze: | OpenAIRE |
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