Hydrogen Storage in Microporous Metal-Organic Frameworks
Nathaniel L. Rosi,1
Juergen Eckert,2,3
Mohamed Eddaoudi,4
David T. Vodak,1
Jaheon Kim,1
Michael O'Keeffe,5
Omar M. Yaghi1*
Metal-organic framework-5 (MOF-5) of composition Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate) with a cubic three-dimensional extended porous structure adsorbed hydrogen up to 4.5 weight percent (17.2 hydrogen molecules per formula unit) at 78 kelvin and 1.0 weight percent at room temperature and pressure of 20 bar. Inelastic neutron scattering spectroscopy of the rotational transitions of the adsorbed hydrogen molecules indicates the presence of two well-defined binding sites (termed I and II), which we associate with hydrogen binding to zinc and the BDC linker, respectively. Preliminary studies on topologically similar isoreticular metal-organic framework-6 and -8 (IRMOF-6 and -8) having cyclobutylbenzene and naphthalene linkers, respectively, gave approximately double and quadruple (2.0 weight percent) the uptake found for MOF-5 at room temperature and 10 bar.
1 Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
2 Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
3 Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
4 Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, SCA 400, Tampa, FL 33620–5250, USA.
5 Department of Chemistry, Arizona State University, Tempe, AZ 85287, USA.
* To whom correspondence should be addressed. E-mail: oyaghi{at}umich.edu
