The Kinetics of the Thermal Decomposition of Aluminum Borohydride¹

Abstract

The exchange reactions of C14Nand S3°" ions with thiocyanate ion have been investigated with essentially negative results.

Hydrogen storage materials

“…Chandra et al reported the transition metal catalyzed dehydrogenation of AB under aqueous conditions and suggest that the activation process takes place on the metal catalyst surface. 14,15 As a plausible mechanism, it is reasonable to consider that there should be interactions between the NH 3 BH 3 molecule and the metal particle surface to form an activated complex which upon attack by a H 2 O molecule readily leads to a concerted dissociation of the B-N bond and hydrolysis of the resulting BH 3…”

“…The latter can also form as a by-product in other mechanically induced processes involving alkali metal borohydrides and transition metal salts 14 (for more examples see the article by G. Soloveichik on page 11).…”

“…Although some additives such as Ti-compounds can substantially enhance the reaction rates for alanates 6 and alane based materials, 7 significant issues remain with respect to the reversibility and stability of these hydride phases. Increasingly, solid-state NMR techniques are being used to evaluate phase compositions and transformations in alanates [8][9][10][11][12][13][14][15] and alane. [16][17][18] Figure 1 presents static and 1 H MAS NMR spectra of a-AlH 3 obtained at the Caltech Solid-State NMR Facility.…”

“…Hydride storage in metal hydrides is promising, but current methods are still expensive and heavy. 14 Another alternative is to store hydrogen covalently in organic molecules. The advantage of storing hydrogen covalently as part of a molecule in comparison with physical trapping of hydrogen gas in a substrate is that the system does not require compression or cryogenic temperatures.…”

“…27 Al MAS NMR also allows detection of aluminum metal and its oxide phases in aluminum-based hydrides during their processing and monitoring both chemical processes and contaminations. [8][9][10][11][12][13][14][15][16][17][18] For example, oxide phases 14 in a-AlH 3 can be clearly identified in the spectrum shown in Figure . NMR analysis of quadrupole nuclei such as 27 Al, 23 Na, 11 B, etc.…”