Dense open metal sites in a microporous metal–organic framework for deep desulfurization with record‐high sulfur dioxide storage density

Abstract

Dry desulfurization employing porous adsorbents is industrially preferred but efficient capture of sulfur dioxide (SO 2 ) at the ultralow concentration (i.e., 2000 ppm) is exceptionally challenging. Metal-organic frameworks with open metal sites (OMSs) can provide sufficient interactions with SO 2 , which, in turn, will degrade or compromise the structural robustness. Herein, we reported Cu-ATC that contains dense oppositely positioned Cu OMSs for efficient trace SO 2 removal. Explicitly, Cu-ATC adsorbs a benchmark amount of SO 2 (5.3 mmol g À1 ) at 0.01 bar with a record-high SO 2 storage density of 2.23 g cm À3 at ambient conditions. The critical role of OMSs has been confirmed by the partially desolvated sample with declined uptakes and adsorption enthalpy. The desulfurization performances have been validated by multicycle breakthrough experiments even with mimic flue-gas and water vapor. Computational simulations identify the adsorption sites at the molecular level. Combined with the high stability under various conditions, Cu-ATC is a potent candidate for industrial implementation.

Boosting trace SO2adsorption and separation performance by the modulation of the SBU metal component of iron-based bimetal MOFs

“…The order of selectivity values of ve materials was consistent with the difference in adsorption capacity between SO 2 and CO 2 . To the best of our knowledge, the IAST selectivity of PCN-250(Fe 2 Zn) was signicantly higher than that of benchmark MOFs such as CPL-1 (8.7) 14 , ELM-12 (30), 31 NH 2 -MIL-125 (42) 24 and MFM-601(32), 10 but still lower than that of some previously reported SO 2 adsorbents such as Mg-gallate (321), 18 CPL-1-NH 2 (485), 37 Cu-ATC (114) 4 and MIL-160 (124). 24…”

“…[1][2][3] Typically, ue gases from fossil fuel combustion contain about 500-3000 ppm of SO 2 , which can react with amine-based CO 2 absorbents signicantly reducing the efficiency of carbon capture. [4][5][6] The current ue gas desulfurization (FGD) technology is mainly wet ue gas desulfurization using alkaline chemical reagent solutions such as CaCO 3 and CaO, which can remove 90-95% of SO 2 . 7 However, the high consumption of fresh water, the residual SO 2 concentration of 150-450 ppm and the tendency to cause secondary pollution make us develop efficient and energy-saving techniques to replace it.…”

“…The rst strategy is to use MOFs with high-density open metal sites (OMSs), since OMSs can form strong adsorption bonds with polarized gas molecules. 2,4,26,27 For example, Wang et al 4 reported an ultra-microporous MOF (Cu-ATC) with a high density of open Cu(II) metal sites, which demonstrated a quite high SO 2 adsorption capacity (3.4 mmol g −1 ) at 0.002 bar and 298 K and considerable SO 2 /CO 2 selectivity (v/v = 10/90, 114). The second strategy is to develop stable MOFs with highdensity hydrogen bond donors.…”

Discovery of anion‐pillared metal–organic frameworks for efficient SO2/CO2 separation via computational screening

“…To date, based on the energy‐saving physisorption separation technology, 17–19 many kinds of adsorbents 20–25 have been studied for SO 2 /CO 2 separation, 26,27 in which metal–organic frameworks (MOFs) have received extensive attention due to their high surface area, structural diversity and so on 28–30 . For example, CPL‐1‐NH 2 exhibits an exceptionally SO 2 /CO 2 selectivity (485) when SO 2 /CO 2 molar ratio is 10/90 at 298 K, but its SO 2 uptake is only 2.29 mmol g −1 at 1.0 bar 31 .…”

SO2 capture and detection with carbon microfibers (CMFs) synthesised from polyacrylonitrile

“…3b). The IAST selectivity result is comparable with similar superficial area BET adsorbents such as zeolite Y (180, 930 m 2 g −1 ), 21 Mg-gallate (321, 576 m 2 g −1 ), 22 Co-gallate (143, 494 m 2 g −1 ), 22 DMOF-TM (169, 900 m 2 g −1 ), 23 MIL-160 (128, 1170 m 2 g −1 ), 24 Cu-ATC (114, 600 m 2 g −1 ), 25 NbOFFIVE-Cu-TPA (78, 1179 m 2 g −1 ). 26 Granted, the SO 2 uptake of CMFs falls short in front of benchmark materials.…”