Neutron scattering studies of hydrogen in potassium–graphite intercalates: Towards tunable graphite intercalates for hydrogen storage

✍ Scribed by Arthur Lovell; Stephen M. Bennington; Neal T. Skipper; Cecilia Gejke; Helen Thompson; Mark A. Adams

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 450 KB
• Volume: 385-386
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.05.311

✦ Synopsis

Low-temperature neutron scattering studies on the ternary graphite intercalation compounds KC 24 ðH 2 Þ x , x ¼ 1; 1:5 show low-energy excitations analogous to those seen in CsC 24 ðH 2 Þ x and RbC 24 ðH 2 Þ x , attributable to the rotational mode of the H 2 split due to the crystal field of the graphene sheets. As in the Cs and Rb-doped systems the hydrogen in KC 24 ðH 2 Þ x also occupies two sites. But no preferential population of sites was observed, implying that both sites fill at lower H 2 concentration than in the Cs and Rb systems. Increasing clattice spacing by doping with deuterated ammonia has the effect of hindering the H 2 adsorption, underlining the importance of an optimised graphite-charging regime to maximise hydrogen storage capability in these systems.