A highly efficient porphyrin-based azo-porous organic polymer for selective CO2 capture and conversion

The greenhouse gas (GHG) emissions from fossil fuel combustion and carbon dioxide (CO2) cause global warming and climate change. In this study, we synthesized three porphyrin-based azo-porous organic polymers (PBPOP1, PBPOP2, and PBPOP3) that enable the capture and one-step conversion of CO2. These catalysts effectively capture the CO2 molecules over N2 in a post-combustion environment. PBPOP3 exhibited an enhanced CO2/N2 selectivity at 313 K, with a value of 534. We characterized the porphyrin-based azo-POPs catalysts using FT-IR, 13C solid-state NMR, XRD, TGA, and HR-FESEM. We evaluated the gas adsorption properties using Brunauer–Emmett–Teller analysis, which included adsorption–desorption isotherms, NLDFT pore-size distribution, and adsorption at 298, 313, and 353 K. The fixation of CO2 with styrene oxide and phenyl glycidyl ether was performed using catalysts for conversion to styrene carbonate (tetra-n-butylammonium bromide was used as a co-catalyst). Thus, our findings can be used for reducing the amount of CO2 gas in the atmosphere by synthesizing porphyrin-based azo-POP catalysts.