Effect of CO on the Cyclic Hydriding-Dehydriding Characteristics of the LaNi5-xAlx(x=0,0.3) Alloys Treated by Anhydrous Hydrogen Fluoride.

DOI Web Site 2 Citations 19 References

Bibliographic Information

Other Title
  • 無水フッ化水素で表面改質したＬａＮｉ５－ｘＡｌｘ（ｘ＝０，０．３）の水素化・脱水素化特性に及ぼすＣＯの影響
  • ムスイ フッカ スイソ デ ヒョウメン カイシツシタ LaNi5-xAlx x

Search this article

Abstract

Hydrogen storage alloys exhibit reversible high-rate hydrogen absorption and desorption reactions. The hydrogen storage density of the alloys is higher than that liquid H2. The exposure of the alloys to impurity gases such as O2, CO, CO2, and H2O readily reduces reactivity with H2 gas. In this study, the surface of LaNi5-xAlx alloy was treated using anhydrous hydrogen fluoride to examine the effect of CO on fluorinated alloy H2 reactivity. This HF treatment effectively reduced alloy surface poisoning by CO. Compared with the initial transfer, the HF-treated alloy still exhibited 80% hydrogen transfer after 100-cycle hydriding-dehydriding reactions in a H2 gas including 1000ppm CO, while the transfer became zero for untreated alloy after five hydriding-dehydriding cycles. AES analysis of HF-treated samples showed that the HF treatment induced the surface segregation of Ni and F atoms where almost no La atoms was detected. The concentration of La atoms was found to increase with depth, in which a mixed region of La, Ni, Al, F, and O atoms was formed. This fluorinated surface layer seems to function both to prevent surface CO poisoning and to act as a catalyst.

Journal

Citations (2)*help

See more

References(19)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top