title: Methane storage capabilities of diamond analogues.
abstract: Methane can be an alternative fuel for vehicular usage provided that new porous materials are developed for its efficient adsorption-based storage. Herein, we search for materials for this application within the family of diamond analogues. We used density functional theory to investigate structures in which tetrahedral C atoms of diamond are separated by -CC- or -BN- groups, as well as ones involving substitution of tetrahedral C atoms with Si and Ge atoms. The adsorptive and diffusive properties of methane are studied using classical molecular simulations. Our results suggest that the all-carbon structure has the highest volumetric methane uptake of 280 VSTP/V at p = 35 bar and T = 298 K. However, it suffers from limited methane diffusion. Alternatively, the considered Si and Ge-containing analogies have fast diffusive properties but their adsorption is lower, ca. 172-179 VSTP/V, at the same conditions.
authors.affiliation: Lawrence Berkeley National Laboratory, One Cyclotron Road, MS 50F-1650, Berkeley, CA 94720-8139, USA. mharanczyk@lbl.gov.
authors.forename: Maciej
authors.initials: M
authors.lastname: Haranczyk
authors.forename: Li-Chiang
authors.initials: LC
authors.lastname: Lin
authors.forename: Kyuho
authors.initials: K
authors.lastname: Lee
authors.forename: Richard L
authors.initials: RL
authors.lastname: Martin
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Neaton
authors.forename: Berend
authors.initials: B
authors.lastname: Smit