An improved synthesis of unsolvated NaB3H8 and its application in preparing Na2B12H12. (14th September 2016)

• Record Type: Journal Article
• Authors: Chen, Weidong; Wu, Guotao; He, Teng; Li, Zhao; Guo, Zaiping; Liu, Huakun; Huang, Zhenguo; Chen, Ping
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 34(2016)
• Page Start: 15471
• Page End: 15476
• Publication Date: 2016-09-14
• Subjects: Octahydrotriborate -- Dodecaborate -- Triborane -- Borane complex -- Hydrogen storage; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.02.143
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Octahydrotriborates are potential hydrogen storage materials and chemical vapor deposition precursors to boride films. Their syntheses have been quite challenging, however. In this paper, an improved facile route for the preparation of unsolvated sodium octahydrotriborate (NaB3 H8 ), which is an important precursor to other octahydrotriborates and derivatives, is reported. The key steps in the synthesis involve dispersing Na finely in inert media and preparing fresh tetrahydrofuran (THF)·BH3 at room temperature. High purity unsolvated NaB3 H8 can be obtained in tens of grams or more in one batch, depending on the reactor size. Using NaB3 H8 as the precursor, sodium dodecaborate (Na2 B12 H12 ) has been successfully synthesized. Both octahydrotriborates and dodecaborates have been observed as intermediates during the thermal dehydrogenation of borohydrides, and their facile syntheses would facilitate mechanistic studies on the hydrogen storage of borohydrides, among other potential applications. Graphical abstract: High purity unsolvated NaB3 H8 can be obtained in tens of grams or more in one batch by reactions between well dispersed Na and freshly prepared THF·BH3 at room temperature. Benefit from the large quantity of NaB3 H8, sodium dodecaborates (Na2 B12 H12 ) has been successfully prepared by directly heat treatment of NaB3 H8 . No high toxic reagent is involved in the whole process. Highlights: An improved route to unsolvated sodium octahydrotriborate (NaB3 H8 ) has been developed. Sodium dodecaborate (Na2 B12 H12 ) has been successfully synthesized using NaB3 H8 . Well dispersed Na can be obtained by ball milling.