摘要
Cationic azole-based metal-organic frameworks(MOFs)with remarkable stability and unique pore environment have aroused great research interests.Meanwhile,flexible MOFs which can undergo pore-structure changes upon exposure to external stimuli are ideal materials for gas separation.However,introducing flexibility into the framework of cationic azole-based MOFs is rarely reported.Herein,we synthesized two stable isomorphic cationic MOFs(M-btz-as,M=Co,Ni)based on a linear azole ligand.After activated at high temperature under vacuum,M-btz-ht(M=Co,Ni)were obtained and both MOFs exhibited flexible features in which Co-btz is more flexible than Ni-btz.Different solvent-mediated activation methods were employed to explore their effects on structural flexibility and produced MOFs with different phases.Continuous phase transformation of Co-btz-e was verified by powder X-ray diffraction.In addition,these MOF phases possessed different gas separation abilities affected by their flexible frameworks,and Co-btz-ht exhibited the highest CO_(2)/CH4 separation ability.
基金
supports from the Fundamental Research Funds for the Central Universities(No.2412019FZ008)
the National Natural Science Foundation of China(Nos.21871105,21503038 and 21531003)
the“111”project(No.B18012).
