An in situ study on the solid state decomposition of ammonia borane: unmitigated by-product suppression by a naturally abundant layered clay mineral

Borazine is a by-product often encountered in the thermal decomposition of ammonia borane, which leads to an inescapable hindrance towards sustainability and cost effectiveness. In this study, a low cost, low surface area clay mineral, bentonite, was modified and introduced as a support material. Bentonite (42.4 m(2) g(-1)) revealed decomposition characteristics comparable to previously reported high surface area (usually 700-1000 m(2) g(-1)) support materials. In addition, borazine formation from bentonite supported ammonia borane was observed to be completely eliminated. Extensive size strain analysis (Williamson-Hall and Warren-Averbach) indicated that the crystalline parameters were observed to be a considerable factor affecting the dehydrogenation reaction along with the high surface area. However, using in situ XRD and MS characterization, the supported decomposition was attributed to a facile pathway, which was dominated by DADB formation. The proposed pathway justifies the borazine elimination and more steady hydrogen release from AB.