Keywords and Phrases
Doped Carbon; Energy Storage; Hydrogen Storage; Metal Hydrides; Nanoconfinement; Nanoporous Carbon
"Recent efforts have demonstrated confinement in porous scaffolds at the nanoscale can alter the hydrogen sorption properties of metal hydrides, though not to an extent feasible for use in onboard hydrogen storage applications, proposing the need for a method allowing further modifications. The work presented here explores how the functionalization of nanoporous carbon scaffold surfaces with heteroatoms can modify the hydrogen sorption properties of confined metal hydrides in relation to non-functionalized scaffolds (FS). Investigations of nanoconfined LiBH4 and NaAlH4 indicate functionalizing the carbon scaffold surface with nitrogen can shift the activation energy of hydrogen desorption in excess of 20 kJ/mol from the activation energy decrease of e 40 kJ/mol obtained from confinement in non-FS. XPS measurements indicate a significant fraction of the nitrogen contained in the carbon scaffolds is pyridinic, suggesting interactions of the available lone electron pair with the confined hydride and decomposition products strongly influences the hydrogen sorption processes. TPD experiments demonstrate nitrogen-FS can stabilize the release of diborane by ~30 °C, and kinetically stabilize LiBH4 against decomposition to higher temperatures. Increased reorientational activation energies measured for the systems with nitrogen-FS using quasielastic neutron scattering support the observed stabilization of LiBH4 is connected with the surface chemistry of the scaffold. Peak rates of hydrogen release occur at higher temperature from NaAlH4 in nitrogen-FS despite the lower measured activation energy, indicating the existence of a rate-limiting step that may be related to the level of scaffold nitrogen doping and the onset of NaAlH4 melting"--Abstract, page iv.
Majzoub, Eric H.
Holmes, Stephen M.
Medvedeva, Julia E.
Ph. D. in Physics
University of Missouri Research Board
National Science Foundation (U.S.)
Integrative Graduate Education Research Traineeship
United States. Department of Energy. Office of Basic Energy Sciences
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Surface-functionalized nanoporous carbons for kinetically stabilized complex hydrides through Lewis acid-Lewis base chemistry
- Anomalous H₂ desorption rate of NaAlH₄ confined in nitrogen-doped nanoporous carbon frameworks
xii, 174 pages
© 2018 Christopher Lee Carr, All rights reserved.
Dissertation - Open Access
Electronic OCLC #
Carr, Christopher L., "Functionalized nanoporous carbon scaffolds for hydrogen storage applications" (2018). Doctoral Dissertations. 2884.