Effect of Functional Groups on the Adsorption of Light Hydrocarbons in fmj-type Metal-Organic Frameworks

The functionalized modification of targeted porous metal-organic frameworks (MOFs) is important to improve the adsorption capacity of light hydrocarbon gases. Five isomorphic MOFs with different functional groups (F, Cl, NH2 , CH3 , and OCH3) are successfully synthesized by systematic functional modification of UMCM-151. By studying the adsorption properties of C-2 and C-3 hydrocarbons (C2H2, C2H4, C2H6, C3H6, and C3H8), it is found that the electron-withdrawing group functional UMCM-151-F and UMCM-151-Cl exhibit strong affinity for C2H2 (98.71 cm(3) g(-1) for UMCM-151-F and 90.29 cm(3) g(-1) for UMCM-151-Cl), while the electron-donating group functional UMCM-151-NH2, UMCM-151-CH3 , and UMCM-151-OCH3 have strong affinity for C2H4 (97.89 cm(3) g(-1) for UMCM-151-NH2, 90.22 cm(3) g(-1) for UMCM-151-CH3 and 94.13 cm(3) g(-1) for UMCM-151-OCH3). The differences in affinity of electron effects for light hydrocarbon provide an experimental basis for porous MOFs to improve their light hydrocarbon storage capacity.