Abstract
The hydrogen sorption properties of calcium borohydride (Ca(BH 4) 2) catalyzed with a small amount of TiF 3, TiCl 3, NbF 5 or NbCl 5 are investigated using thermal analyses and X-ray diffraction. NbF 5 exhibits the best performance among all the catalysts; it causes a decrease in the hydrogen desorption temperature which leads to hydrogen absorption at practical temperature and pressure conditions. The hydrogen content of Ca(BH 4) 2 with NbF 5 reaches about 5.0 wt.% after hydrogen absorption at 693 K for 24 h under 90 bar of hydrogen. The main dehydrogenation product of Ca(BH 4) 2 with NbF 5 is a CaH 2− x F x solid solution with a CaF 2 (C1) structure, while pure Ca(BH 4) 2 produces CaH 2 after hydrogen desorption.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have