ガス水素の時間分解の局所中性子 difraktion 研究:構造II (sII) から構造I (sI) に変換する
Y Halpern1, V Thieu, R W Henning
1Energy Systems Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Journal of the American Chemical Society
|December 26, 2001
まとめ
研究者らは,ガス水素格子構造の構造IIから構造Iへの変換を,in situ微分法を用いて観察した. この構造の変化は,アルゴン水合物におけるCO2のガス交換によって引き起こされ,混合水合物を形成した.
科学分野:
- マテリアルサイエンス 材料科学
- クリスタルグラフィーです.
- 物理化学 物理化学
背景:
- ガス水素は,明確な結晶構造 (例えば,構造Iと構造II) を表しています.
- ガス水化合物の相変遷を理解することは,エネルギー貯蔵や炭素結合を含む様々な用途において極めて重要です.
研究 の 目的:
- 構造II (sII) のガス水素格子から構造I (sI) の格子への in situ 変換を調査する.
- ゲスト分子交換によって誘発される構造変化のメカニズムを解明する.
主な方法:
- 飛行時間による中性子粉の difraktion が in situ 観測に使用されました.
- 実験は230〜263Kの温度,最大5000psiの圧力で実施された.
- 脱塩氷結晶は,水素形成のためのアルゴンガス,交換のためのCO2と,出発材料として使用されました.
主要な成果:
- 加熱すると,D(2) O氷からsIIアルゴン水素化物への完全な変換が観察されました.
- sIIアルゴン水素は,COに曝露されたときにsI水素に成功裏に変換されました.
- その結果,sI水素はアルゴン/CO2の混合水素として識別され,ゲスト分子の交換を示した.
結論:
- クラトラート水素構造は,特定の条件下で,異なる格子 (sII から sI) の間で変換することができます.
- ゲスト分子交換は,ガス水素の構造変化を誘発する有効なメカニズムです.
- ガス水素は,封装された分子の交換を可能にする均衡システムとして振る舞う.
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