Structure and Dynamics of Molecular Hydrogen in the Interlayer Pores of a Swelling 2:1 Clay by Neutron Scattering

• DOI: 10.1021/jp5082356
• Publication Date: 2014-10-11T02:24:22Z
• Authors: Jacqueline S. Edge; Neal T. Skipper; Felix Fernandez-A...; Arthur Lovell; Gadipelli Srinivas; Stephen M. Bennin...; Victoria Garcia S...; Tristan G. A. Youngs
• Keywords: Quasielastic neutron scattering

Neutron scattering has been used to reveal the structure and dynamics of molecular H2 physisorbed into two-dimensional pores sparingly hydrated Ca-laponite clay. Thermal pretreatment clay at 415 K under vacuum yielded an interlayer composition in 1.0–1.5 water molecules per Ca2+ cation range provided a vacant gallery height 2.82 Å. This value is very well matched diameter hydrogen allows intercalation up point where liquid-like monolayer formed within At low coverage 0.1 isosteric heat adsorption 9.2 kJ mol–1. Quasielastic neutron experiments conducted 40–100 two populations First, we find that are localized close partially cations. Second, identify more mobile population whose motion captured by jump diffusion. 40 K, diffusion coefficient 2.3 ± 0.5 × 10–5 cm2 s–1. order magnitude slower than extrapolated from bulk liquid H2.