硼氫化銨
外觀
硼氫化銨 | |||
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英文名 | Ammonium borohydride Ammonium tetrahydroborate | ||
別名 | 四氫合硼酸銨 | ||
識別 | |||
CAS號 | 19193-35-2 ![]() | ||
性質 | |||
化學式 | NH4BH4 | ||
外觀 | 白色晶體[1] | ||
結構 | |||
晶體結構 | 面心立方(岩鹽結構)[2] | ||
空間群 | Fm3m[2] | ||
相關物質 | |||
其他陰離子 | 氫化銨 | ||
其他陽離子 | 硼氫化鈉 硼氫化鉀 | ||
相關化學品 | 硼烷氨 氮化硼 | ||
若非註明,所有數據均出自標準狀態(25 ℃,100 kPa)下。 |
硼氫化銨是一種無機化合物,化學式為NH4BH4,是一種在室溫下不穩定的白色晶體,於1958年被發現。它是目前已知氫含量最高(ρm = 24.5 wt% H2)的固體化合物。[3]
製備
[編輯]硼氫化鈉和氟化銨在−60 °C(或−78 °C[3])的液氨中反應,可以得到NH4BH4和NaF。[4]
- NaBH4 + NH4F → NH4BH4 + NaF
硼氫化鈉和硫酸銨在四氫呋喃中的反應會有NH4BH4作為中間體產生,它會和之後生成的NH3BH3反應,進一步生成[(NH3)2BH2]BH4、B3N3H6等產物。[4]
- NH4BH4 + NH3BH3 → [(NH3)2BH2]BH4 + H2
性質及結構
[編輯]硼氫化銨在−40 °C開始分解,25 °C經過6 h便只剩50%,分解反應的產物是[BNH6]x和氫氣。[1]在固態時,它的分解產物是(NH3BH3)2;在含有痕量氨的乙醚中,它分解為NH3BH3。它在液氨中穩定。[5]
NH4BH4在1.5 GPa開始發生相變,由α相轉變為β相,並在3.4~4.6 GPa轉變為γ相。[6]
參考文獻
[編輯]- ^ 1.0 1.1 R. W. Parry, D. R. Schultz, P. R. Girardot. The Preparation and Properties of Hexamminecobalt(III) Borohydride, Hexamminechromium(III) Borohydride and Ammonium Borhydride 1. Journal of the American Chemical Society. 1958-1, 80 (1): 1–3 [2019-04-01]. ISSN 0002-7863. doi:10.1021/ja01534a001. (原始內容存檔於2020-11-07) (英語).
- ^ 2.0 2.1 Karkamkar, Abhijeet; Kathmann, Shawn M.; Schenter, Gregory K.; Heldebrant, David J.; Hess, Nancy; Gutowski, Maciej; Autrey, Tom. Thermodynamic and Structural Investigations of Ammonium Borohydride, a Solid with a Highest Content of Thermodynamically and Kinetically Accessible Hydrogen. Chemistry of Materials. 2009, 21 (19): 4356–4358. ISSN 0897-4756. doi:10.1021/cm902385c.
- ^ 3.0 3.1 Thomas K. Nielsen, Abhi Karkamkar, Mark Bowden, Flemming Besenbacher, Torben R. Jensen, Tom Autrey. Methods to stabilize and destabilize ammonium borohydride. Dalton Trans. 2013, 42 (3): 680–687 [2019-04-01]. ISSN 1477-9226. doi:10.1039/C2DT31591B (英語).
- ^ 4.0 4.1 P. Veeraraghavan Ramachandran, Ameya S. Kulkarni. The role of ammonia in promoting ammonia borane synthesis. Dalton Transactions. 2016, 45 (41): 16433–16440 [2019-04-01]. ISSN 1477-9226. doi:10.1039/C6DT02925F (英語).
- ^ David J. Heldebrant, Abhi Karkamkar, John C. Linehan, Tom Autrey. Synthesis of ammonia borane for hydrogen storage applications. Energy & Environmental Science. 2008, 1 (1): 156 [2019-04-01]. ISSN 1754-5692. doi:10.1039/b808865a (英語).
- ^ Roxana Flacau, Yansun Yao, Dennis D. Klug, Serge Desgreniers, Christopher I. Ratcliffe. Structural phase transitions induced by pressure in ammonium borohydride. Physical Chemistry Chemical Physics. 2012, 14 (19): 7005 [2019-04-01]. ISSN 1463-9076. doi:10.1039/c2cp40160f (英語).
拓展閱讀
[編輯]
- Tom Autrey. Chemical approaches to on-board hydrogen storage. The road to reversibility in "Inorganic hydrides". Preprints - American Chemical Society, Division of Energy & Fuels, 2014. 59 (1): 4. CODEN: PACSCT.
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