To develop continuous hydrogen generators utilizing ammonia borane (AB), one of the extensively studied chemical hydrogen storage material for applications in polymer electrolyte membrane fuel cells (PEMFCs), various types of oxygen-containing compounds such as 18-crown-6, 18-crown-6 derivatives, glycols, and polyethylene glycols were examined as chemical additives to enhance the H2-release properties of AB. The rate and extent of AB dehydrogenation with these promoters were found to increase considerably at temperatures ranging from 85 °C to 125 °C; in particular, a mixture of AB and either 18-crown-6 or tetraethylene glycol afforded a material-based hydrogen storage capacity of >9.5 wt%. In situ Fourier transform infrared (FT-IR) and solid-state nuclear magnetic resonance (NMR) spectroscopic studies were conducted to identify gaseous byproducts potentially detrimental to a PEMFC. Density functional theory (DFT) studies demonstrated that the additives could interact with AB via hydrogen bonding between oxygen atoms of a promoter and N-H of AB, which could ultimately facilitate AB dehydrogenation.
Bibliographical notePublisher Copyright:
© 2014 Hydrogen Energy Publications, LLC.Published by Elsevier Ltd. All rights reserved.
- Ammonia borane
- Chemical hydride
- Hydrogen storage
- Polymer electrolyte membrane fuel cell (PEMFC)
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology