Direct observation of dimethyl sulfide trapped by MOF proving efficient removal of sulfur impurities

Here, we report the adsorptive removal of trace amounts of dimethyl sulfide (DMS) using metal-organic frameworks (MOFs). Cu²⁺-based MOFs with open metal sites (OMSs), [Cu₃(btc)₂] (HKUST-1), where btc = 1,3,5-benzenetricarboxylate, and without OMSs, [Cu₂(bdc)₂(dabco)] (Cu-JAST-1), where bdc = 1,4-benzenedicarboxylate and dabco = 1,4-diazabicyclo[2.2.2]octane, were investigated for the removal of DMS to compare their performance with that of Ag-Y zeolite, which is currently widely used in industry. HKUST-1 exhibited a considerably higher adsorption capacity for DMS than the other adsorbents, which was confirmed by breakthrough measurements. The adsorption state of DMS with HKUST-1 was directly revealed by single-crystal X-ray diffraction (SXRD) analysis and in situ Raman spectroscopy. In addition, it was shown that DMS can be removed by HKUST-1 even under humid conditions.