Carbon Dioxide Adsorption within Porous Porphyrin Networks

Abstract

Porphyrin-based films containing nanoscale crystallites of covalent organic frameworks (MPOR-COFs, where M = H 2 , Cu 2+ , Zn 2+ ) have been synthesized, and their adsorption properties have been studied. The adsorption isotherms for CO 2 indicate distinct variations in adsorption energetics and capacity among films prepared with different porphyrin precursors. H 2 POR-COF films exhibited enhanced CO 2 capture performance compared to those containing zinc and copper in their porphyrin rings. The heat of adsorption and the adsorption capacity for the metal-free films were about 50% lower and 100% higher than those of the metal-containing films. Increased crystallinity in the films was found to reduce their CO 2 adsorption capacities. This work highlights the viability of our synthetic approach to create tunable porphyrin-based frameworks for gas separation applications.