Conventional SO 2 scrubbing agents, namely calcium oxide and zeolites, are often used to remove SO 2 using a strong or irreversible adsorption-based process. However, adsorbents capable of sensing and selectively capturing this toxic molecule in a reversible manner, with in-depth understanding of structure–property relationships, have been rarely explored. Here we report the selective removal and sensing of SO 2 using recently unveiled fluorinated metal–organic frameworks (MOFs). Mixed gas adsorption experiments were performed at low concentrations ranging from 250 p.p.m. to 7% of SO 2. Direct mixed gas column breakthrough and/or column desorption experiments revealed an unprecedented SO 2 affinity for KAUST-7 (NbOFFIVE-1-Ni) and KAUST-8 (AlFFIVE-1-Ni) MOFs. Furthermore, MOF-coated quartz crystal microbalance transducers were used to develop sensors with the ability to detect SO 2 at low concentrations ranging from 25 to 500 p.p.m.
Removal of SO 2 from flue gas is of prime importance to avoid its poisoning of CO 2-seperating agents. Here, the authors demonstrate that two fluorinated metal–organic frameworks selectively remove SO 2 from synthetic flue gas and can sense SO 2 with p.p.m.-level detection using quartz crystal microbalance transducers.