title: A comparative investigation of H(2) adsorption strength in Cd- and Zn-based metal organic framework-5.
abstract: Hydrogen binding energies for the primary and secondary adsorption sites in the Cd- and Zn-based metal organic framework-5 (MOF-5) were studied using density functional theory. Out of the three exchange-correlation functionals employed in our study, we find that the local density approximation yields a qualitatively correct description of the interaction strengths of H(2) in MOF-5 systems. The H(2) adsorption energies for all trapping sites in Zn- and Cd-based MOF-5 are seen to be of the same order of magnitude but with a generally stronger binding in Cd-based MOF-5 as compared to Zn-based MOF-5. In particular, the H(2) binding energy at the secondary adsorption sites in Cd-based MOF-5 is increased by around 25% compared to Zn-based MOF-5. This result suggests that Cd-based MOF-5 would be better suited to store hydrogen at higher temperatures than Zn-based MOF-5.
authors.affiliation: Condensed Matter Theory Group, Department of Physics and Materials Science, Uppsala University, Box 530, SE-751 21 Uppsala, Sweden.
authors.forename: Pornjuk
authors.initials: P
authors.lastname: Srepusharawoot
authors.forename: C Moysés
authors.initials: CM
authors.lastname: Araújo
authors.forename: Andreas
authors.initials: A
authors.lastname: Blomqvist
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Scheicher
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ahuja