Synthesis of Fe/M (M = Mn, Co, Ni) bimetallic metal organic frameworks and their catalytic activity for phenol degradation under mild conditions

Partial isomorphic substitution of iron in an Fe(BDC)(DMF,F) metal organic framework by manganese, cobalt, and nickel has been described for the first time. Specifically, different amounts of Mn, Co and Ni have been incorporated into the Fe-based framework during a solvothermal crystallization procedure. Several characterization techniques, including XRD, FT-IR, SEM, EDS, TG, XPS and ICP-AES, strongly support the effective incorporation of Mn, Ni and Co into material frameworks. The catalytic performance of these materials was examined in liquid-phase degradation of phenol at 35 °C and near neutral pH of 6.2. The results show that the degradation efficiency can be evidently improved by the incorporation of Mn, while it can be inhibited by the incorporation of Ni. The incorporation of Co shows no remarkable influence on the degradation process. Moreover, the ratios of n(Fe)/n(Mn) in the bimetallic MOFs have a strong impact on the degradation process. The stability and reusability of these catalysts under mild conditions were also demonstrated in this study. This work illustrates the potential of bimetallic MOF structures in developing active heterogeneous catalysts for the degradation process of toxic compounds.