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Towards General Network Architecture Design Criteria for Negative Gas Adsorption Transitions in Ultraporous Frameworks

preprint
submitted on 12.03.2019 and posted on 13.03.2019 by Simon Krause, Jack D. Evans, Volodymyr Bon, Irena Senkovska, Paul Iacomi, Felicitas Kolbe, Sebastian Ehrling, Erik Troschke, Jürgen Getzschmann, Daniel D. Többens, Alexandra Franz, Dirk Wallacher, Pascal G. Yot, Guillaume Maurin, Eike Brunner, Philip L. Llewellyn, François-Xavier Coudert, Stefan Kaskel

Critical design criteria for negative gas adsorption (NGA), a counterintuitive feature of pressure amplifying materials, hitherto uniquely observed in a highly porous framework compound (DUT-49), are derived by analysing the physical effects of micromechanics, pore size, interpenetration, adsorption enthalpies, and the pore filling mechanism using advanced in situ X-ray and neutron diffraction, NMR spectroscopy, and calorimetric techniques parallelized to adsorption for a series of six isoreticular networks. Aided by computational modelling, we identify DUT-50 as a new pressure amplifying material featuring distinct NGA transitions upon methane and argon adsorption. In situ neutron diffraction analysis of the methane (CD4) adsorption sites at 111 K supported by grand canonical Monte Carlo simulations reveals a sudden population of the largest mesopore to be the critical filling step initiating structural contraction and NGA. In contrast, interpenetration leads to framework stiffening and specific pore volume reduction, both factors effectively suppressing NGA transitions.

Funding

European Research Council grant agreement No. 742743

Marie Sklodowska-Curie grant agreement No 641887 (project acronym: DEFNET)

BMBF (No. 05K16OD1)

History

Email Address of Submitting Author

simon.krause@tu-dresden.de

Institution

Technische Universität Dresden

Country

Germany

ORCID For Submitting Author

0000-0001-9504-8514

Declaration of Conflict of Interest

There are no conflicts to declare.

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