Porous Polybenzimidazoles via Template‐Free Suzuki Coupling Polymerization: Preparation, Porosity, and Heterogeneous Catalytic Activity in Knoevenagel Condensation Reactions

Suzuki coupling polymerization between boronic acids and halo‐benzimidazole provides a new alternative approach to prepare polybenzimidazoles. PPBIs (PPBI‐1 and PPBI‐2) with porous structures are prepared through a template‐free synthetic route. The Brunauer–Emmett–Teller specific surface areas for PPBI‐1 and PPBI‐2 are 385 and 158 m 2 g −1 , respectively. Based on the hydrogen physisorption isotherms measured at 77 K and a pressure up to 1.13 bar, PPBI‐1 exhibits a hydrogen uptake of 0.83 wt% at 1.13 bar and 77 K. An increase in the carbon dioxide loading capacity with increasing specific surface area is observed, in which PPBI‐1 shows higher carbon dioxide uptake (8.0 wt%) than PPBI‐2 (6.1 wt%) at 1.0 bar and 273 K. Additionally, the prepared PPBIs can act as a heterogeneous catalyst for Knoevenagel reaction.