266233 Catalytic Effect of Boric Acid On Thermal Dehydrogeantion of Ammonia Borane

Tuesday, October 30, 2012: 1:45 PM
305 (Convention Center )
Hyun Tae Hwang, Ahmad Al-Kukhun, Patrick Greenan and Arvind Varma, School of Chemical Engineering, Purdue University, West Lafayette, IN

Ammonia borane (AB, NH3BH3) is a promising hydrogen storage material for use in proton exchange membrane (PEM) fuel cell applications. In this study, the effect of boric acid on AB dehydrogenation was investigated. Our study shows that boric acid is a promising additive to decrease onset temperature as well as to increase hydrogen release kinetics for AB thermolysis. Using boric acid, we obtained high H2 yield (11.5 wt% overall H2 yield, 2.23 H2 equivalent) at 85°C, PEM fuel cell operating temperatures, along with rapid kinetics. In addition, only trace amount of NH3 (20-30 ppm) was detected in the gaseous product. Studies to identify the catalytic mechanism of boric acid were also conducted. The spent AB solid product was found to be polyborazylene-like species, which can be efficiently regenerated using currently demonstrated methods. The results indicate that our proposed method is promising for hydrogen storage, and could be used in PEM fuel cell based vehicles.

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