Dramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materials

Handle URI:
http://hdl.handle.net/10754/598018
Title:
Dramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materials
Authors:
Nugent, Patrick; Pham, Tony; McLaughlin, Keith; Georgiev, Peter A.; Lohstroh, Wiebke; Embs, Jan Peter; Zaworotko, Michael J.; Space, Brian; Eckert, Juergen
Abstract:
The effects of pore size reduction on the dynamics of hydrogen sorption in metal-organic materials (MOMs) were elucidated by studying SIFSIX-2-Cu and its doubly interpenetrated polymorph SIFSIX-2-Cu-i by means of sorption, inelastic neutron scattering (INS), and computational modeling. SIFSIX-2-Cu-i exhibits much smaller pore sizes, which possess high H2 sorption affinity at low loadings. Experimental H2 sorption measurements revealed that the isosteric heat of adsorption (Qst) for H2 in SIFSIX-2-Cu-i is nearly two times higher than that for SIFSIX-2-Cu (8.6 vs. 4.6 kJ mol-1). The INS spectrum for H2 in SIFSIX-2-Cu-i is rather unique for a porous material, as only one broad peak appears at low energies near 6 meV, which simply increases in intensity with loading until the pores are filled. The value for this rotational transition is lower than that in most neutral metal-organic frameworks (MOFs), including those with open Cu sites (8-9 meV), which is indicative of a higher barrier to rotation and stronger interaction in the channels of SIFSIX-2-Cu-i than the open Cu sites in MOFs. Simulations of H2 sorption in SIFSIX-2-Cu-i revealed two hydrogen sorption sites in the MOM: direct interaction with the equatorial fluorine atom (site 1) and between two equatorial fluorine atoms on opposite walls (site 2). The calculated rotational energy levels and rotational barriers for the two sites in SIFSIX-2-Cu-i are in good agreement with INS data. Furthermore, the rotational barriers and binding energies for site 2 are slightly higher than that for site 1, which is consistent with INS results. The lowest calculated transition for the primary site in SIFSIX-2-Cu is also in good agreement with INS data. In addition, this transition in the non-interpenetrating material is higher than any of the sites in SIFSIX-2-Cu-i, which indicates a significantly weaker interaction with the host as a result of the larger pore size. This journal is © the Partner Organisations 2014.
Citation:
Nugent P, Pham T, McLaughlin K, Georgiev PA, Lohstroh W, et al. (2014) Dramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materials. Journal of Materials Chemistry A 2: 13884. Available: http://dx.doi.org/10.1039/c4ta02171a.
Publisher:
Royal Society of Chemistry (RSC)
Journal:
Journal of Materials Chemistry A
KAUST Grant Number:
FIC/2010/06
Issue Date:
21-Jul-2014
DOI:
10.1039/c4ta02171a
Type:
Article
ISSN:
2050-7488; 2050-7496
Sponsors:
B.S. acknowledges the National Science Foundation (Award no. CHE-1152362) and the computational resources that were made available by an XSEDE Grant (no. TG-DMR090028). The authors also thank Dr Jonathan L. Belof for discussions on the two-dimensional quantum rotation calculations. This publication is also based on work supported by Award no. FIC/2010/06, made by the King Abdullah University of Science and Technology (KAUST). This work is based in part upon experiments performed at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. This research project has also been supported by the European Commission under the 7th Framework Programme through the 'Research Infrastructures action of the 'Capacities' Programme, NMI3-II Grant number 283883. One of us (P.A.G) gratefully acknowledges financial support by the Project BeyondEverest under EU programme REGPOT-2011-1.
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Full metadata record

DC FieldValue Language
dc.contributor.authorNugent, Patricken
dc.contributor.authorPham, Tonyen
dc.contributor.authorMcLaughlin, Keithen
dc.contributor.authorGeorgiev, Peter A.en
dc.contributor.authorLohstroh, Wiebkeen
dc.contributor.authorEmbs, Jan Peteren
dc.contributor.authorZaworotko, Michael J.en
dc.contributor.authorSpace, Brianen
dc.contributor.authorEckert, Juergenen
dc.date.accessioned2016-02-25T13:11:05Zen
dc.date.available2016-02-25T13:11:05Zen
dc.date.issued2014-07-21en
dc.identifier.citationNugent P, Pham T, McLaughlin K, Georgiev PA, Lohstroh W, et al. (2014) Dramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materials. Journal of Materials Chemistry A 2: 13884. Available: http://dx.doi.org/10.1039/c4ta02171a.en
dc.identifier.issn2050-7488en
dc.identifier.issn2050-7496en
dc.identifier.doi10.1039/c4ta02171aen
dc.identifier.urihttp://hdl.handle.net/10754/598018en
dc.description.abstractThe effects of pore size reduction on the dynamics of hydrogen sorption in metal-organic materials (MOMs) were elucidated by studying SIFSIX-2-Cu and its doubly interpenetrated polymorph SIFSIX-2-Cu-i by means of sorption, inelastic neutron scattering (INS), and computational modeling. SIFSIX-2-Cu-i exhibits much smaller pore sizes, which possess high H2 sorption affinity at low loadings. Experimental H2 sorption measurements revealed that the isosteric heat of adsorption (Qst) for H2 in SIFSIX-2-Cu-i is nearly two times higher than that for SIFSIX-2-Cu (8.6 vs. 4.6 kJ mol-1). The INS spectrum for H2 in SIFSIX-2-Cu-i is rather unique for a porous material, as only one broad peak appears at low energies near 6 meV, which simply increases in intensity with loading until the pores are filled. The value for this rotational transition is lower than that in most neutral metal-organic frameworks (MOFs), including those with open Cu sites (8-9 meV), which is indicative of a higher barrier to rotation and stronger interaction in the channels of SIFSIX-2-Cu-i than the open Cu sites in MOFs. Simulations of H2 sorption in SIFSIX-2-Cu-i revealed two hydrogen sorption sites in the MOM: direct interaction with the equatorial fluorine atom (site 1) and between two equatorial fluorine atoms on opposite walls (site 2). The calculated rotational energy levels and rotational barriers for the two sites in SIFSIX-2-Cu-i are in good agreement with INS data. Furthermore, the rotational barriers and binding energies for site 2 are slightly higher than that for site 1, which is consistent with INS results. The lowest calculated transition for the primary site in SIFSIX-2-Cu is also in good agreement with INS data. In addition, this transition in the non-interpenetrating material is higher than any of the sites in SIFSIX-2-Cu-i, which indicates a significantly weaker interaction with the host as a result of the larger pore size. This journal is © the Partner Organisations 2014.en
dc.description.sponsorshipB.S. acknowledges the National Science Foundation (Award no. CHE-1152362) and the computational resources that were made available by an XSEDE Grant (no. TG-DMR090028). The authors also thank Dr Jonathan L. Belof for discussions on the two-dimensional quantum rotation calculations. This publication is also based on work supported by Award no. FIC/2010/06, made by the King Abdullah University of Science and Technology (KAUST). This work is based in part upon experiments performed at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. This research project has also been supported by the European Commission under the 7th Framework Programme through the 'Research Infrastructures action of the 'Capacities' Programme, NMI3-II Grant number 283883. One of us (P.A.G) gratefully acknowledges financial support by the Project BeyondEverest under EU programme REGPOT-2011-1.en
dc.publisherRoyal Society of Chemistry (RSC)en
dc.titleDramatic effect of pore size reduction on the dynamics of hydrogen adsorbed in metal–organic materialsen
dc.typeArticleen
dc.identifier.journalJournal of Materials Chemistry Aen
dc.contributor.institutionUniversity of South Florida Tampa, Tampa, United Statesen
dc.contributor.institutionUniversita degli Studi di Milano, Milan, Italyen
dc.contributor.institutionSofia University St. Kliment Ohridski, Sofia, Bulgariaen
dc.contributor.institutionTechnische Universitat Munchen, Munich, Germanyen
dc.contributor.institutionPaul Scherrer Institut, Villigen, Switzerlanden
dc.contributor.institutionUniversity of Limerick, Limerick, Irelanden
kaust.grant.numberFIC/2010/06en
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