Towards general network architecture design criteria for negative gas adsorption transitions in ultraporous frameworks

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

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Apr 09, 2019

Received Date: 19th March 19

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.

Read in full at ChemRxiv.

This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.

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Nature Communications

Nature Research, Springer Nature