Triptycene based microporous hypercrosslinked polymer with amino functionality for selective <scp>CO₂</scp> capture

Abstract The increasing CO 2 concentration in the atmosphere contributes significantly to global warming, necessitating effective capture techniques. Though amine‐based solvents are commonly used, they have drawbacks like high energy consumption and corrosion. Physical adsorption using microporous sorbents with polar groups emerges as a promising alternative, offering high efficiency and selectivity for CO 2 capture. This work presents the design of a new microporous hypercrosslinked polymer with amino groups derived from the 3D molecular building block triptycene (TBMP‐NH 2 ), for CO 2 capture applications. The triptycene unit in the polymer backbone provides high surface area, thermal stability, and microporosity. TBMP‐NH 2 demonstrates excellent thermal stability ( T d &gt; 350°C), considerable microporosity, and a high BET‐specific surface area of 866 m 2 /g, making it a promising microporous adsorbent. It exhibits a high CO 2 adsorption capacity of 1.86 mmol/g at 273 K and 1.23 mmol/g at 298 K, with a Q st value of 33.95 kJ/mol, indicating a physisorption mechanism where the micropore volume ( V mic = 0.359 cm 3 /g) plays a crucial role. TBMP‐NH 2 displays good CO 2 /N 2 and CO 2 /CH 4 selectivity, outperforming several reported porous polymers. Owing to its high physiochemical and thermal properties, and efficient and selective CO 2 capture ability, TBMP‐NH 2 can be considered a promising material for CO 2 capture and environmental remediation application.