Trace SO₂ capture within the engineered pore space using a highly stable SnF₆^2--pillared MOF.

Area of Science:

• Materials Science
• Environmental Chemistry
• Adsorption Science

Background:

• Industrial desulfurization requires efficient capture of trace sulfur dioxide (SO2) under ambient conditions.
• Developing stable and selective solid sorbents remains a significant challenge for SO2 removal.

Purpose of the Study:

• To develop a highly stable fluorinated metal-organic framework (MOF) for effective SO2 capture.
• To investigate the SO2 adsorption performance, selectivity, and regeneration capabilities of SNFSIX-Cu-TPA.

Main Methods:

• Synthesis and characterization of SNFSIX-Cu-TPA, a fluorinated MOF with SnF6(2-) pillars.
• Gas adsorption isotherms (SO2, CO2, N2) and computational simulations to assess affinity.
• Ideal Adsorbed Solution Theory (IAST) for selectivity prediction.
• Dynamic breakthrough experiments and in situ thermogravimetric analysis (TGA) for performance evaluation.

Main Results:

• SNFSIX-Cu-TPA exhibits remarkable SO2 uptake (2.22 mmol g-1) at 298 K and 0.002 bar.
• High selectivity for SO2 over CO2 and N2, with an IAST selectivity of 148 for SO2/CO2 separation.
• Effective removal of trace SO2 from simulated flue gas with a dynamic capacity of 1.52 mmol g-1.
• Demonstrated efficient and reversible SO2 capture over 20 cycles.

Conclusions:

• SNFSIX-Cu-TPA is a promising durable material for SO2 capture due to its exceptional performance, selectivity, and mild regeneration.
• This MOF offers a viable solution for realistic industrial desulfurization processes.