CTAB-controlled synthesis of phenolic resin-based nanofiber aerogels for highly efficient and reversible SO2 capture

Currently available aerogels as effective adsorption materials for capture of trace sulfur dioxide (SO2) are unfavorable from the perspective of deep desulfurization technologies. Herein, four phenolic resin-based aerogels with controlled structures varying from spherical (∼1 μm) to nanofiber (∼20 nm) were prepared and characterized using hexadecyl trimethyl ammonium bromide (CATB) as a soft template. It is demonstrated that adjusting the usage amount of CTAB from 0.00 to 0.15 g could effectively regulate SO2 adsorption capacities of phenolic resin-based aerogels. AG-0.15 nanofiber aerogel exhibited an outstanding SO2 uptake through a swelling mechanism (10.58 mmol g−1 at 298.2 K, 1.0 bar), and displayed a very high SO2/N2 selectivity (7271 at 298.2 K). Moreover, AG-0.15 nanofiber aerogel also had excellent performance for selective capture of 2000 ppm SO2 in the mixed SO2/N2/CO2 gases through dynamic column breakthrough experiments. Overall, phenolic resin-based nanofiber aerogels are perceived as a promising adsorbent for effective removal of trace SO2 from flue gas.