Metalloporphyrin functionalized multivariate IRMOF-74-IV analogs for photocatalytic CO2 reduction

Metal-organic frameworks (MOFs) are widely employed as functional materials in various fields, while intriguing properties for specific applications have been pursued all along with their development. Herein, we adopt a ligand substitution strategy to functionalize the mesoporous IRMOF-74-IV for multivariate MOF catalysts. With similar size and geometry, the porphyrin ligand 4,4′-(porphyrin-5,15-diyl)bis(2-hydroxybenzolate) (PBHB2–) was mixed with the 3,3′″-dihydroxy-2′,2″,5′,5″-tetramethyl-[1,1′:4′,1″:4″,1″′-quaterphenyl]-4,4″′-dicarboxylate (L-IV2–) ligand in synthesis, giving porphyrin functionalized IRMOF-74-IV analogs. Compared with IRMOF-74-IV, the IRMOF-74-IV-PBHBX-M series show improved stability and performance in photocatalytic CO2 reduction. After tuning the contents of porphyrin ligand and the species of metal ion, IRMOF-74-IV-PBHB45%-Cu demonstrates to be the best as an efficient photocatalyst for the CO2-to-CO conversion. This work has achieved to tailor extant MOFs through a mixed-ligand approach, which would contribute to more multivariate materials and unlock new opportunities for their applications.