Highly Selective SO₂ Capture by Triazine-Functionalized Triphenylamine-Based Nanoporous Organic Polymers

Area of Science:

• Materials Science
• Environmental Chemistry
• Polymer Chemistry

Background:

• Sulfur dioxide (SO2) emissions from combustion pose significant environmental and public health risks.
• Existing adsorbent polymers struggle with low SO2/CO2 and SO2/N2 selectivity, hindering efficient capture.
• Development of advanced materials for selective SO2 adsorption is a critical environmental challenge.

Purpose of the Study:

• To synthesize and characterize novel triazine-functionalized triphenylamine-based nanoporous organic polymers (ANOPs).
• To evaluate the SO2 adsorption capacity and selectivity of ANOP-6 and ANOP-7 for SO2/CO2 and SO2/N2 mixtures.
• To assess the potential of ANOPs for efficient SO2 capture from flue gas.

Main Methods:

• Synthesis of ANOP-6 and ANOP-7 via cost-effective Friedel-Crafts reactions.
• Characterization of polymer structure and ultramicroporous properties.
• Measurement of static SO2 adsorption isotherms and dynamic breakthrough tests for gas mixture separation.

Main Results:

• ANOPs exhibit high SO2 adsorption capacities (up to 9.94 mmol·g-1 at 1 bar).
• ANOP-6 demonstrates exceptional selectivity for SO2/CO2 (248) and SO2/N2 (13146) at 298 K and 1 bar.
• Dynamic breakthrough tests confirm superior SO2 separation from SO2/CO2/N2 mixtures with a breakthrough time of 73.1 min·g-1.

Conclusions:

• Triazine-functionalized triphenylamine-based ANOPs show remarkable SO2 adsorption and selectivity.
• These polymers surpass existing triazine-based materials in SO2/CO2 and SO2/N2 separation performance.
• ANOPs hold significant promise for highly efficient SO2 capture from industrial flue gases.