Highly Efficient and Reversible CO₂ Capture from Ambient Air by Tunable Anion-Functionalized Macroporous Resin

Capturing CO₂ from ambient air is one of the greatest challenges of all time. Even though its concentration is approximately 0.04%, this tiny fraction still holds the power to reshape the whole climate system. The difficulty lies in the fact that the regeneration of current sorbents is highly expensive, diluted, sensitive to moisture, and suffers energy penalties. Herein, we address these challenges by developing highly efficient and thermally regenerable anion-functionalized resins (AFRs), which were synthesized by immobilizing different basic anions on the macroporous PS-DVB framework. These AFRs were characterized using FTIR, BET, and SEM methods and then tested under ambient conditions for CO₂ of 400 ppm and 30 °C, where optimized AFRs [R][3ATri] exhibited a high capacity of 2.12 mmol/g and excellent recycling. The adsorption mechanism between the anion and CO₂ was explained through FTIR, solid-state ¹³C NMR, and DFT methods. This method provides a scalable and power-efficient platform for next-generation DAC technologies to interface between molecular design and implementation.