title: Expanded Porphyrins as Two-Dimensional Porous Membranes for CO2 Separation.
abstract: Porphyrin-based two-dimensional polymers have uniform micropores and close to atom-thin thicknesses, but they have not been explored for gas separation. Herein we design various expanded porphyrin derivatives for their potential application in membrane gas separation, using CO2/N2 as an example. Pore sizes are determined based on both van der Waals radii and electron density distribution. Potential energy curves for CO2 and N2 passing through are mapped by dispersion-corrected density functional theory calculations. The passing-through barriers are used to evaluate CO2/N2 separation selectivity. Promising subunits for CO2 separation have been selected from the selectivity estimates. 2D membranes composed of amethyrin derivatives are shown to have high ideal selectivity on the order of 10(6) for CO2/N2 separation. Classical molecular dynamics simulation yields a permeance of 10(4)-10(5) GPU for CO2 through extended 2D membranes based on amethyrin derivatives. This work demonstrates that porphyrin systems could offer an attractive bottom-up approach for 2D porous membranes.
authors.affiliation: †Department of Chemistry, University of California, Riverside, California 92521, United States.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Tian
authors.affiliation: ‡Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201, United States.|§Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996-1600, United States.
authors.forename: Sheng
authors.initials: S
authors.lastname: Dai
authors.affiliation: †Department of Chemistry, University of California, Riverside, California 92521, United States.
authors.forename: De-en
authors.initials: DE
authors.lastname: Jiang
keywords: 2-dimensional polymer; CO2 capture; dispersion-corrected DFT; gas separation; ultrathin membrane