Investigation of the effect of functional groups on gas adsorption in a MOF of a given structure is undoubtedly very important because it facilitates targeting porous MOFs with enhanced storage capacities by ligand fu...Investigation of the effect of functional groups on gas adsorption in a MOF of a given structure is undoubtedly very important because it facilitates targeting porous MOFs with enhanced storage capacities by ligand functionalization.In this work,we chose an NbO-type MOF platform to evaluate the impact of organic functional groups on C_(2)H_(2)adsorption.Correspondingly,we synthesized five diisophthalate ligands with the same length but different organic functionalities(NH_(2),CH_(3),NO_(2),F,and CF_(3)),and successfully incorporated them into MOFs with underlying NbO topology.C_(2)H_(2)adsorption experiments reveal that these functional moieties can enhance the affinity towards C_(2)H_(2),but not all these compounds outperformed the unfunctionalized parent compound NOTT-101 in terms of C_(2)H_(2)uptake.At 298 K and 1 atm,the C_(2)H_(2)uptake varies from 153.7 to 193.8 cm^(3)(STP)g^(−1),depending on the attached organic functional groups.Particularly,the amine group-functionalized compound ZJNU-34(NH_(2))exhibits the maximum C_(2)H_(2)uptake of the six compounds evaluated,reaching as high as 203.6 cm^(3)(STP)g^(−1)at 295 K and 1 atm.Such a 10%increase of C_(2)H_(2)uptake compared to the parent compound might be attributed to acid-base and/or hydrogen-bonding interactions between the NH_(2)groups with adsorbed C_(2)H_(2)molecules.The fundamental understanding of the impact of functional groups on C_(2)H_(2)adsorption demonstrated in this work provides valuable information for future designing of porous MOFs with enhanced acetylene-storage capacities.展开更多
基金supported by the Natural Science Foundation of Zhejiang province,China(LR16B010001)the National Natural Science Foundation of China(no.21301156)the Qianjiang Talents Project in Zhejiang province(ZC304015017).
文摘Investigation of the effect of functional groups on gas adsorption in a MOF of a given structure is undoubtedly very important because it facilitates targeting porous MOFs with enhanced storage capacities by ligand functionalization.In this work,we chose an NbO-type MOF platform to evaluate the impact of organic functional groups on C_(2)H_(2)adsorption.Correspondingly,we synthesized five diisophthalate ligands with the same length but different organic functionalities(NH_(2),CH_(3),NO_(2),F,and CF_(3)),and successfully incorporated them into MOFs with underlying NbO topology.C_(2)H_(2)adsorption experiments reveal that these functional moieties can enhance the affinity towards C_(2)H_(2),but not all these compounds outperformed the unfunctionalized parent compound NOTT-101 in terms of C_(2)H_(2)uptake.At 298 K and 1 atm,the C_(2)H_(2)uptake varies from 153.7 to 193.8 cm^(3)(STP)g^(−1),depending on the attached organic functional groups.Particularly,the amine group-functionalized compound ZJNU-34(NH_(2))exhibits the maximum C_(2)H_(2)uptake of the six compounds evaluated,reaching as high as 203.6 cm^(3)(STP)g^(−1)at 295 K and 1 atm.Such a 10%increase of C_(2)H_(2)uptake compared to the parent compound might be attributed to acid-base and/or hydrogen-bonding interactions between the NH_(2)groups with adsorbed C_(2)H_(2)molecules.The fundamental understanding of the impact of functional groups on C_(2)H_(2)adsorption demonstrated in this work provides valuable information for future designing of porous MOFs with enhanced acetylene-storage capacities.
