Document Detail


High-capacity methane storage in metal-organic frameworks M2(dhtp): the important role of open metal sites.
MedLine Citation:
PMID:  19275154     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Abstract/OtherAbstract:
We found that metal-organic framework (MOF) compounds M(2)(dhtp) (open metal M = Mg, Mn, Co, Ni, Zn; dhtp = 2,5-dihydroxyterephthalate) possess exceptionally large densities of open metal sites. By adsorbing one CH(4) molecule per open metal, these sites alone can generate very large methane storage capacities, 160-174 cm(3)(STP)/cm(3), approaching the DOE target of 180 cm(3)(STP)/cm(3) for material-based methane storage at room temperature. Our adsorption isotherm measurements at 298 K and 35 bar for the five M(2)(dhtp) compounds yield excess methane adsorption capacities ranging from 149 to 190 cm(3)(STP)/cm(3) (derived using their crystal densities), indeed roughly equal to the predicted, maximal adsorption capacities of the open metals (within +/-10%) in these MOFs. Among the five isostructural MOFs studied, Ni(2)(dhtp) exhibits the highest methane storage capacity, approximately 200 cm(3)(STP)/cm(3) in terms of absolute adsorption, potentially surpassing the DOE target by approximately 10%. Our neutron diffraction experiments clearly reveal that the primary CH(4) adsorption occurs directly on the open metal sites. Initial first-principles calculations show that the binding energies of CH(4) on the open metal sites are significantly higher than those on typical adsorption sites in classical MOFs, consistent with the measured large heats of methane adsorption for these materials. We attribute the enhancement of the binding strength to the unscreened electrostatic interaction between CH(4) and the coordinatively unsaturated metal ions.
Authors:
Hui Wu; Wei Zhou; Taner Yildirim
Related Documents :
15252654 - Fused pyridazines: rigid multidentates for designing and fine-tuning the structure of h...
22181894 - Novel superhard carbon: c-centered orthorhombic c_{8}.
20366484 - Structure and properties of an amorphous metal-organic framework.
23421504 - Control of gold nanoparticle superlattice properties via mesogenic ligand architecture.
20505984 - Aqueous ferrofluids as templates for magnetic hydroxyapatite nanocomposites.
23424554 - 9-(2,4-dinitro-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-1h-xanthene-1,8(2h)...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  131     ISSN:  1520-5126     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-04-01     Completed Date:  2009-06-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  4995-5000     Citation Subset:  -    
Affiliation:
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Reassessment of the reaction mechanism in the heme dioxygenases.
Next Document:  Evaluating precision and accuracy when quantifying different endogenous control reference genes in m...