The hydrogenation behavior of 3CaH(2)+4MgB(2)+CaF2 composite was studied by manometric measurements, powder X-ray diffraction, differential scanning calorimetry and attenuated total reflection infrared spectroscopy. The maximum observed quantity of hydrogen loaded in the composite was 7.0 wt%. X-ray diffraction showed the formation of Ca(BH4)(2) and MgH2 after hydrogenation. The activation energy for the dehydrogenation reaction was evaluated by DSC measurements and turns out to be 162 +/- 15 kJ mol(-1) H-2. This value decreases due to cycling to 116 +/- 5 kJ mol(-1) H-2 for the third dehydrogenation step. A decrease of ca. 25-50 degrees C in dehydrogenation temperature was observed with cycling. Due to its high capacity and reversibility, this composite is a promising candidate as a potential hydrogen storage material.
Sorption and desorption properties of a CaH2/MgB2/CaF2 Reactive Hydride Composite as potential hydrogen storage material
ZAVOROTYNSKA, Olena;BARICCO, Marcello;
2011-01-01
Abstract
The hydrogenation behavior of 3CaH(2)+4MgB(2)+CaF2 composite was studied by manometric measurements, powder X-ray diffraction, differential scanning calorimetry and attenuated total reflection infrared spectroscopy. The maximum observed quantity of hydrogen loaded in the composite was 7.0 wt%. X-ray diffraction showed the formation of Ca(BH4)(2) and MgH2 after hydrogenation. The activation energy for the dehydrogenation reaction was evaluated by DSC measurements and turns out to be 162 +/- 15 kJ mol(-1) H-2. This value decreases due to cycling to 116 +/- 5 kJ mol(-1) H-2 for the third dehydrogenation step. A decrease of ca. 25-50 degrees C in dehydrogenation temperature was observed with cycling. Due to its high capacity and reversibility, this composite is a promising candidate as a potential hydrogen storage material.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
