Ca(BH4)2鈭扢gF2 Reversible Hydrogen Storage: Reaction Mechanisms and Kinetic Properties

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• 作者：Rapee Gosalawit-Utke ; Karina Suarez ; Jose M. Bellosta von Colbe ; Ulrike Bo虉senberg ; Torben R. Jensen ; Yngve Cerenius ; Christian Bonatto Minella ; Claudio Pistidda ; Gagik Barkhordarian ; Matthias Schulze ; Thomas Klassen ; Ru虉diger Bormann ; Martin Dornheim
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：March 10, 2011
• 年：2011
• 卷：115
• 期：9
• 页码：3762-3768
• 全文大小：1074K
• 年卷期：v.115,no.9(March 10, 2011)
• ISSN：1932-7455

文摘

A composite of Ca(BH₄)₂鈭扢gF₂ is proposed as a reversible hydrogen storage system. The dehydrogenation and rehydrogenation reaction mechanisms are investigated by in situ time-resolved synchrotron radiation powder X-ray diffraction (SR-PXD) and Raman spectroscopy. The formation of an intermediate phase (CaF_2鈭?i>xH_x) is observed during rehydrogenation. The hydrogen content of 4.3 wt % is obtained within 4 h during the first dehydrogenation at isothermal and isobaric conditions of 330 掳C and 0.5 bar H₂, respectively. The cycling efficiency is evaluated by three release and uptake cycles together with absorbed hydrogen content in the range 5.1鈭?.8 wt % after 2.5 h (T = 330 掳C and p(H₂) = 130 bar). The kinetic properties on the basis of hydrogen absorption are comparable for all cycles. As compared to pure Ca(BH₄)₂ and Ca(BH₄)₂鈭扢gH₂ composite, Ca(BH₄)₂鈭扢gF₂ composite reveals the kinetic destabilization and the reproducibility of hydrogen storage capacities during cycling, respectively.