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

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Direct air capture (DAC) of carbon dioxide (CO2) is crucial for climate change mitigation.
• Current DAC sorbents face challenges including high regeneration costs, low capacity, moisture sensitivity, and energy penalties.
• Efficient CO2 capture from ambient air (approx. 400 ppm) remains a significant technological hurdle.

Purpose of the Study:

• To develop novel, efficient, and thermally regenerable anion-functionalized resins (AFRs) for direct air capture of CO2.
• To overcome the limitations of existing sorbent materials used in DAC technologies.
• To provide a scalable and energy-efficient platform for next-generation DAC.

Main Methods:

• Synthesis of anion-functionalized resins (AFRs) by immobilizing basic anions on a porous polymer framework (PS-DVB).
• Characterization of AFRs using Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and scanning electron microscopy (SEM).
• Performance testing of AFRs for CO2 adsorption under ambient conditions (400 ppm CO2, 30 °C) and evaluation of regeneration efficiency.

Main Results:

• Optimized AFRs, specifically [R][3ATri], demonstrated a high CO2 adsorption capacity of 2.12 mmol/g.
• The developed AFRs exhibited excellent recyclability and thermal regenerability.
• Adsorption mechanisms were elucidated using FTIR, solid-state 13C NMR, and density functional theory (DFT) calculations.

Conclusions:

• Anion-functionalized resins (AFRs) present a promising, efficient, and cost-effective solution for direct air capture of CO2.
• The developed materials offer a scalable and power-efficient platform for advancing DAC technologies.
• This research bridges molecular design with practical implementation for next-generation carbon capture.