Selectivity trend of gas separation through nanoporous graphene

Journal Article · Wed Apr 15 04:00:00 EDT 2015 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2014.01.030· OSTI ID:22475550

Liu, Hongjun ^[1]; Chen, Zhongfang ^[2]; Dai, Sheng ^[1]; Jiang, De-en ^[1]

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1. Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)
2. Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00931 (United States)

By means of molecular dynamics (MD) simulations, we demonstrate that porous graphene can efficiently separate gases according to their molecular sizes. The flux sequence from the classical MD simulation is H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4}, which generally follows the trend in the kinetic diameters. This trend is also confirmed from the fluxes based on the computed free energy barriers for gas permeation using the umbrella sampling method and kinetic theory of gases. Both brute-force MD simulations and free-energy calcualtions lead to the flux trend consistent with experiments. Case studies of two compositions of CO{sub 2}/N{sub 2} mixtures further demonstrate the separation capability of nanoporous graphene. - Graphical abstract: Classical molecular dynamics simulations show the flux trend of H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4} for their permeation through a porous graphene, in excellent agreement with a recent experiment. - Highlights: • Classical MD simulations show the flux trend of H{sub 2}>CO{sub 2}≫N{sub 2}>Ar>CH{sub 4} for their permeation through a porous graphene. • Free energy calculations yield permeation barriers for those gases. • Selectivities for several gas pairs are estimated from the free-energy barriers and the kinetic theory of gases. • The selectivity trend is in excellent agreement with a recent experiment.

• OSTI ID: 22475550
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 224; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ARGON
CARBON DIOXIDE
COMPUTERIZED SIMULATION
FREE ENERGY
GASES
GRAPHENE
HYDROGEN
MEMBRANES
METHANE
MIXTURES
MOLECULAR DYNAMICS METHOD
POROUS MATERIALS
REDUCTION
SAMPLING