The hydrogen storage properties of Fe2(dobdc) (dobdc4− = 2,5-dioxido-1,4-benzenedicarboxylate) and an oxidized analog, Fe2(O2)(dobdc), have been examined using several complementary techniques, including low-pressure gas adsorption, neutron powder diffraction, and inelastic neutron scattering. These two metal–organic frameworks, which possess one-dimensional hexagonal channels decorated with unsaturated iron coordination sites, exhibit high initial isosteric heats of adsorption of −9.7(1) and −10.0(1) kJ mol−1, respectively. Neutron powder diffraction has allowed the identification of three D2 binding sites within the two frameworks, with the closest contacts corresponding to Fe–D2 separations of 2.47(3) and 2.53(5) Å, respectively. Inelastic neutron scattering spectra, obtained from p-H2 (para-H2) and D2–p-H2 mixtures adsorbed in Fe2(dobdc), reveal weak interactions between two neighboring adsorption sites, a finding that is in opposition to a previous report of possible ‘pairing’ between neighboring H2 molecules.
You have access to this article
Please wait while we load your content...
Something went wrong. Try again?