Electronic nature of linkers-based conjugated microporous polymers: a sustainable approach to enhance CO2 capture

Abstract

Conjugated microporous polymers (CMPs) represent a promising class of materials with diverse applications due to their unique chemophysical characteristics. We introduce a novel approach for developing a TPPDA–TPA CMP- and TPPDA–ThZ CMP-based dynamic tetraphenyl-p-phenylenediamine (TPPDA) unit employing the optimum conditions for the Suzuki protocol. These CMPs incorporate triphenylamine (TPA) and 4,7-di(thiophen-2-yl)benzo[c]thiadiazole (ThZ), and exhibit distinct electronic properties. Our CMPs demonstrate high thermal durability (char yield up to 69.5 wt%) and significant surface areas (up to 132 m² g⁻¹). The TPPDA–TPA CMP shows a notable presence of nucleophilic bonding sites, enhancing the selective uptake of CO₂, with around twofold-higher CO₂ uptake (27.49 cm³ g⁻¹) compared with TPPDA–ThZ CMP (14.67 cm³ g⁻¹). Additionally, we evaluate the selectivity of CO₂ over N₂ gases on TPPDA CMPs. We analyze CO₂ uptake based on key thermodynamic and kinetic principles, including the Clausius–Clapeyron equation and Henry's law. This research offers a promising strategy for enhancing CO₂-adsorption capacities on CMPs.