Designing Triazine-Based Aminal-Linked Porous Organic Polymers for Efficient CO ₂ Capture and Conversion

The steady rise in atmospheric CO 2 levels has led to a serious environmental threat in the form of global warming and climate change. Therefore, the development of efficient porous nanomaterials as adsorbent and catalyst that simultaneously capture CO 2 and catalytically convert it into value-added chemicals is a very challenging area of research today. Herein, we report the synthesis of three nitrogen-rich, aminal-linked porous organic polymers (POPs), namely, TBAL-POP-3, TBAL-POP-4, and TBAL-POP-5, constructed via extended Schiff-base condensation reaction under solvothermal conditions. Among the three polymers, TBAL-POP-5 exhibits the highest specific surface area (1053 m 2 g −1 ), highest fraction of hierarchical mesopores (84%), and high CO 2 uptake capacity of 1.92 mmol g −1 at 273 K and 1 bar and good CO 2 /N 2 selectivity 43.82/32.03 at 273/298 K. The enhanced gas adsorption performance of TBAL-POP-5 is attributed to its mesopore-enriched hierarchical structure, which facilitates efficient mass transfer and active site accessibility. Furthermore, these materials demonstrated good catalytic activity toward the formylation of amines using CO 2 as a sustainable C1 source in the presence of dimethylamine borane as a green reducing agent. This work highlights the dual functionality of nitrogen-rich porous polymers as multifunctional platforms for integrated CO 2 capture and its reductive valorization.