Vapor-assisted preparation of Mn/Fe/Co/Zn–Cu bimetallic metal–organic frameworks based on octahedron micron crystals (PCN-6′)

Abstract

A Cu-based metal–organic framework (PCN-6′) with octahedral crystal morphology was synthesized using a strong acid (HCl) and characterized by SEM, TGA and BET, which showed a larger specific surface area and pore volume than the corresponding counterpart that was prepared using a weak acid (oxalate). The bimetallic PCN-6′(M) (M = Mn/Fe/Co/Zn) series of materials was obtained using a vapor-assisted solid-phase method and the exchanged second metal content reached 18.4% for Mn, 19.5% for Fe, 11.7% for Co, and 16.8% for Zn, respectively. Based on the CO2 and H2 adsorption results, the open bimetallic sites on PCN-6′(M) exhibit a better adsorption performance than PCN-6′, especially in the low-pressure region.