Efficient SO 2 Removal Using a Microporous Metal–Organic Framework with Molecular Sieving Effect

Removal of trace SO 2 contaminants from gas mixtures by the molecular sieving effect is highly desired. Herein, a microporous metal–organic framework Cu 2 (pzdc) 2 (pyz) [CPL-1, pzdc = 2,3-pyrazinedicarboxylate; pyz = pyrazine] with a dumbbell-shaped 1D channel and specific binding sites is explored for deep desulfurization. The proper size of 4.1 × 6.2 Å and strong SO 2 trapping sites on CPL-1 render a high adsorption uptake of SO 2 (44.8 cm 3 g –1 ) with a record-high selectivity for SO 2 /N 2 (368) and SO 2 /CH 4 (74.3) separation under ambient conditions. Moreover, the dispersion-corrected density functional theory calculations have identified the dual specific adsorption sites of SO 2, such as S δ+ ···O δ− electrostatic interactions and O δ− ···H δ+ hydrogen bonds. The feasibility of CPL-1 for SO 2 /N 2, SO 2 /CH 4, CO 2 /CH 4, CO 2 /N 2, and mimicked flue gas mixture separations was validated by dynamic breakthrough experiments. Water vapor and CO 2 impurity were introduced to the gas feed streams to confirm the excellent separation performance of CPL-1. Moreover, a scale-up production of CPL-1 via a facile and green method was conducted, and a reproducible CPL-1 adsorbent with undamaged adsorption and separation performances was successfully manufactured in kilogram quantity. These unique features render CPL-1 a very promising adsorbent for practical desulfurization processes.