Solid-State NMR Study of Li-Assisted Dehydrogenation of Ammonia Borane
| Title | Solid-State NMR Study of Li-Assisted Dehydrogenation of Ammonia Borane |
| Publication Type | Journal Article |
| Year of Publication | 2012 |
| Authors | Kobayashi T, Hlova IZ, Singh NK, Pecharsky VK, Pruski M |
| Journal Title | Inorganic Chemistry |
| Volume | 51 |
| Pages | 4108-4115 |
| Date Published | 04 |
| Type of Article | Article |
| ISBN Number | 0020-1669 |
| Accession Number | WOS:000302186600031 |
| Keywords | alkali-metal amidoboranes, angle-spinning, boron-nitride, chemical hydrogen storage, complex hydrides, lithium hydride, mas-nmr, nmr, QUADRUPOLAR NUCLEI, systems, thermal-decomposition |
| Abstract | The mechanism of thermochemical dehydrogenation of the 1:3 mixture of Li3AlH6 and NH3BH3 (AB) has been studied by the extensive use of solid-state NMR spectroscopy and theoretical calculations. The activation energy for the dehydrogenation is estimated to be 110 kJ mol(-1), which is lower than for pristine AB (184 kJ mol(-1)). The major hydrogen release from the mixture occurs at 60 and 72 degrees C, which compares favorably with pristine AB and related hydrogen storage materials, such as lithium amidoborane (LiNH2BH3, LiAB). The NMR studies suggest that Li3AlH6 improves the dehydrogenation kinetics of AB by forming an intermediate compound (LiAB)(x)(AB)(1-x). A part of AB in the mixture transforms into LiAB to form this intermediate, which accelerates the subsequent formation of branched polyaminoborane species and further release of hydrogen. The detailed reaction mechanism, in particular the role of lithium, revealed in the present study highlights new opportunities for using ammonia borane and its derivatives as hydrogen storage materials. |
| URL | <Go to ISI>://WOS:000302186600031 |
| DOI | 10.1021/ic202368a |
| Alternate Journal | Inorg. Chem. |
