Improved Structural Design and CO2 Capture of Porous Hydroxy-Rich Polymeric Organic Frameworks

Abstract

Polymeric organic frameworks (POFs) are tunable and robust porous materials with potential applications for gas capture, catalysis, and separations technologies. A se- ries of new porous POFs have been synthesized from the reaction of phloroglucinol or resorcinol derivatives with aryl aldehyde precursors. The monomers have var- ious molecular shapes including linear, bent, trigonal, and tetrahedral geometries. Depending on the size and geometric matching of the monomers, the polymers are dominantly microporous with some mesoporous character or they are non-porous. In addition to standard spectroscopic and surface characterization, the materials were screened as adsorbents for carbon dioxide capture at low pressure (0-1 bar). The best performing material (POF 1D) has a CO2 capture capacity of 9.0 wt. % (2.04 mmol g􀀀1) at 298 K and 1 bar which is comparable to other polymeric organic frameworks. Isosteric heats of adsorption for POF 1A, POF 2A, and POF 2B were found to be dependent on the weight percent of CO2 adsorbed: this suggests there are both chemisorptive and physisorptive components of CO2 capture by the POFs.