title: Predicting low-pressure O(2) adsorption in nanoporous framework materials for sensing applications.
abstract: A set of 98 nanoporous framework material (NFM) structures was investigated by classical Grand canonical Monte Carlo simulations for low-pressure O2 adsorption properties (Henry's constant and isosteric heat of adsorption). The set of materials includes those that have shown high O2 uptake experimentally as well as a subset of more than 2000 structures previously screened for noble-gas uptake. While use of the general force field UFF is fruitful for noble-gas adsorption studies, its use is shown to be limited for the case of O2 adsorption-one distinct limitation is a lack of sufficient O2 -metal interactions to be able to describe O2 interaction with open metal sites. Nonetheless, those structures without open metal sites that have very small pores (<2.5 Å) show increased O2 /N2 selectivity. Additionally, O2 /N2 mixture simulations show that in some cases, H2 O or N2 can hinder O2 uptake for NFMs with small pores due to competitive adsorption.
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185 (USA), Fax: (+1) 505 844 7354.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Zeitler
authors.forename: Timothy
authors.initials: T
authors.lastname: Van Heest
authors.forename: David S
authors.initials: DS
authors.lastname: Sholl
authors.forename: Mark D
authors.initials: MD
authors.lastname: Allendorf
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Greathouse
keywords: Monte Carlo simulations; metal-organic frameworks; oxygen adsorption; porous materials; sensors