title: Unusual adsorption site behavior in PCN-14 metal-organic framework predicted from Monte Carlo simulation.
abstract: The adsorption equilibrium of methane in PCN-14 was simulated by the Monte Carlo technique in the grand canonical ensemble. A new force field was proposed for the methane/PCN-14 system, and the temperature dependence of the molecular siting was investigated. A detailed study of the statistics of the center of mass and potential energy showed a surprising site behavior with no energy barriers between weak and strong sites, allowing open metal sites to guide methane molecules to other neighboring sites. Moreover, this study showed that a model assuming weakly adsorbing open metal clusters in PCN-14, densely populated only at low temperatures (below 150 K), can explain published experimental data. These results also explain previously observed discrepancies between neutron diffraction experiments and Monte Carlo simulations.
authors: Departamento de Engenharia Química, Grupo de Pesquisa em Separações por Adsorção (GPSA), Universidade Federal do Ceará, Campus do Pici, Bl. 709, 60455-760 Fortaleza, CE, Brazil.
authors: Sebastião M P
authors: SM
authors: Lucena
authors: Paulo G M
authors: PG
authors: Mileo
authors: Pedro F G
authors: PF
authors: Silvino
authors: Célio L
authors: CL
authors: Cavalcante