Multiscale Co-Assembly to Meso-Macroporous Foamed Single-Crystal Metal-Organic Frameworks for the Supported Capture of Sulfur Dioxide

The introduction of enlarged and interconnected nanochannels into metal-organic frameworks (MOFs) overcome their micropore size restriction, enhances mass transportation, and improves the accessibility of anchored metal clusters. Herein, foamed Ce-MOF single crystals (F-Ce-MOF-SC-x) designed from a multiscale co-assembly is reported in the presence of a copolymer template and 1,3,5-trimethylbenzene as a structural regulator. The resultant F-Ce-MOF-SC-x possessed well-defined microporous tandem-ordered meso-macroporous foams with superior connectivity and versatile Ce-defective unsaturated sites (Ce-DUS). F-Ce-MOF-SC-x is applied as a stable carrier for anchoring polytertiary amines (PA) via coordination interactions with Ce-DUS. Owing to the superior ability of PA to recognize SO2, the resultant F-Ce-MOF-SC-x@yPA delivers exceptional performance in terms of the high-temperature reversible adsorption and separation of SO2, including a remarkable capacity for SO2, spectacular selectivity for SO2/CO2/N-2, an ultrafast adsorption equilibrium rate, and stability for 50 cycles. These characteristics are outstanding among those of MOFs and superior to those of many reported SO2 adsorbents.