Fluorescent Microporous Polyimides based on Perylene and Triazine for Highly CO₂-Selective Carbon Materials

Carbon dioxide (CO₂) capture from point sources like coal-fired power plants is a potential solution for stabilizing atmospheric CO₂ content to avoid global warming. Sorbents with high and reversible CO₂ uptake, high CO₂ selectivity, good chemical and thermal stability, and low cost are desired for the separation of CO₂ from N₂ in flue or natural gas. We report here, for the first time, on the synthesis of new microporous polyimide (PI) networks from the condensation of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and 1,3,5-triazine-2,4,6-triamine (melamine) using a Lewis acid catalyst zinc acetate/imidazole complex. These PI network materials, prepared in the absence and presence of dimethyl sulfoxide (DMSO) as weak solvent template, exhibit strong fluorescence. Nitrogen-containing carbons can be accessed from our PI networks via a simple thermal pyrolysis route. The successful construction of new microporous PI networks and derived N-containing carbons is shown here to provide promising CO₂ sorbents with high uptake capacities (15 wt %) combined with exceptional selectivities over N₂ (240), while their fluorescent properties can be exploited for simple sensing.