Metal‐containing hydrogen‐bonded organic frameworks with alternating electrostatic environments for trace
SO
2
capture
Jiali Fu, Yu‐Hao Gu, Qingxue Hui, Xiangyang Zhang, Deli Li, Kuan Lu, Ye Xu, Chaoyue Fang, Xiuyuan Feng, Xufei Li, Shuai Yuan, Jianming Pan, Qi Ding, Zhaoqiang Zhang Abstract
Trace SO 2 capture from flue gas remains challenging in deep desulfurization because of its low partial pressure, corrosive conditions, and competition from coexisting gases. Here, we present a family of isostructural metal‐containing hydrogen‐bonded organic frameworks (M‐HOFs) featuring alternating electrostatic pore environments for efficient trace SO 2 capture. All M‐HOFs exhibit SO 2 uptakes higher than 2.76 mmol g −1 at 0.2 kPa and 298 K, while Ni‐HOF delivers a SO 2 packing density of 3.23 g cm −3 at 100 kPa, surpassing that of solid SO 2 . M‐HOFs show high SO 2 /CO 2 selectivities (>600 for a 0.2/99.8 mixture) and low uptakes of CH 4 , N 2 , and O 2 , enabling efficient deep desulfurization under simulated flue‐gas conditions. Breakthrough and cycling experiments at SO 2 concentrations of 2000–3000 ppm confirm robust deep‐desulfurization performance, highlighting M‐HOFs as promising adsorbents for practical SO 2 removal. Crystal structure and spectroscopic analyses support cooperative host‐guest interactions within confined micropores lined by alternating positive and negative electrostatic sites.