Sulfone-functionalized metal–organic framework aerogels for selective CO2 capture from natural gas

The accumulation of CO2 in natural gas may reduce the heating value and even pose a risk of corrosion in transport pipelines, making the effective removal of CO2 highly essential. Metal–organic frameworks (MOFs), known for their high specific area and large porosity, show promising application in CO2 capture. However, a major obstacle is their intrinsic fragility and poor physicochemical stability. Herein, we present a sulfone-incorporated in-situ growth and fiber freeze-shaping strategy to develop lightweight, robust, and multiscale porous sulfone-functionalized UiO-67 (UiO-67-SO2) aerogels supported by aramid nanofibers. The resulting UiO-67-SO2 aerogels exhibit remarkable structural features, including a high MOF loading mass (64.39 wt%), low density (5.31 mg/cm3), high specific surface area (769.98 m2g−1), and large porosity (99.24 %). Moreover, owing to the introduction of CO2-philic sulfone groups, the UiO-67-SO2 aerogels exhibit high CO2 adsorption capacity (5.88 mmol/g), a high CO2/CH4 adsorption selectivity (43), and only a 2.77 % decline in their initial CO2 adsorption capacity after 10 cycles. The adsorption energy calculated by density functional theory method further confirms the strong interactions between UiO-67-SO2 aerogels and CO2 molecules. This work presents a promising direction for developing multiscale porous UiO-67-SO2 aerogels for the highly selective removal of CO2 from natural gas.