Cyclotrimerization Polymers as Precursors for Tailored Porous Carbons and Application in Supercapacitors

Porous carbon materials are considered ideal candidates for electric double-layer capacitor (EDLC) electrodes owing to their high surface area, electrical conductivity, and chemical stability. The use of synthetic polymers as carbon precursors is an advantageous synthesis approach that enables molecular-level control over doping, porosity, and other properties for enhanced electrochemical performance. Highly conjugated polymeric frameworks obtained via the triple aldol condensation reaction of different diacetyl-containing compounds: 2,2'-diacetylbiphenyl, 4,4'-diacetylbiphenyl, and 1,4-diacetylbenzene, serve as efficient precursors for carbon materials, giving good yields upon high-temperature pyrolysis. The three precursors differ in their molecular frameworks and extent of conjugation, allowing an investigation of the relationship between precursor structure, graphitization, and porosity in the resulting carbons. Our results demonstrate that precursor structural effects become increasingly significant at lower carbonization temperatures, where conjugation and framework rigidity appear to play a role in graphitic ordering. At higher temperatures, several factors, including ease of molecular mobility and the release of volatile components, influence graphitization. The porosity of the resulting carbon materials is correlated with the structural characteristics of the precursor polymers, reflecting the differences in their molecular architecture. These findings highlight the importance of precursor design in tailoring porosity, while temperature remains the dominant factor in controlling graphitization.