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 C2 and C3 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 cm3 g–1 for UMCM-151-F and 90.29 cm3 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 cm3 g–1 for UMCM-151-NH2, 90.22 cm3 g–1 for UMCM-151-CH3 and 94.13 cm3 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.