Enhanced gas separation performance of an ultramicroporous pillared-layer framework induced by hanging bare Lewis basic pyridine groups

• Published in: Dalton transactions : an international journal of inorganic chemistry 2018-07, Vol.47 (28), p.931-9316
• Main Authors: Li, Haipeng, Li, Shu'ni, Hou, Xiangyang, Jiang, Yucheng, Hu, Mancheng, Zhai, Quan-Guo
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Functional groups; Gas separation; Hydrocarbons; Metal-organic frameworks; Methane; Pore size; Porosity; Porous materials; Synergistic effect
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt01592a

Pillared-layer metal-organic frameworks show great promise for gas storage and separation because their pore size as well as functionality usually can be controlled and adjusted synergistically. By combining the common pyridine and carboxylate groups, we design herein a new 3D pillared-layer framework, [Co 2 (DBPT)(BPY) 2 (CO 3 )] n ( SNNU-95 ). Dinuclear [Co 2 ] motifs are connected by DBPT ligands to form a 2D layer, which is further bridged by BPY to obtain the 3D pillar-layered framework of SNNU-95 . Remarkably, two un-coordinated pyridine groups of DBPT not only help stabilize the 2D layer through π π stacking but also point into the 1D channels to create an ultramicroporous environment. Taking advantage of the ultramicroporosity and pyridine Lewis basic sites, SNNU-95 shows not only extra high CO 2 over CH 4 and C 2 hydrocarbons over CH 4 selectivity, but also remarkable C 2 H 2 /CO 2 , C 2 H 2 /C 2 H 4 , and C 2 H 4 /CO 2 separation under ambient conditions. This synergistic effect resulting from functional groups and pore size provides a promising route to design porous materials for the highest possible gas uptake and separation performance. An ultramicroporous pillared-layer framework exhibits extra high CO 2 and C 2 hydrocarbons over CH 4 separation performance under ambient conditions induced by hanging bare Lewis basic pyridine groups on the pore surface.