A range of multifunctional magnetic metal–organic framework nanomaterials consisting of various mass ratios of the metal–organic framework MIL-53(Fe) and magnetic SiO2@NiFe2O4 nanoparticles were designed, prepared, characterized, and evaluated as heterogeneous catalysts for the Knoevenagel condensation. The as-fabricated nanomaterials, especially the nanocatalyst MIL-53(Fe)@SiO2@NiFe2O4(1.0), showed good catalytic performance in the Knoevenagel condensation at room temperature as a result of synergistic interaction between the Lewis acid iron sites of MIL-53(Fe) and the active sites of the magnetic SiO2@NiFe2O4 nanoparticles. In addition, the heterogeneous catalyst was readily recovered and a recycling test showed that it could be reused for five times without significant loss of its catalytic activity, making it economical and environmentally friendly.
一系列多功能磁性金属-有机框架纳米材料,由金属-有机框架MIL-53(Fe)和磁性SiO2@NiFe2O4纳米颗粒的不同质量比组成,被设计、制备、表征和评估作为Knoevenagel缩合的非均相催化剂。特别是制备的纳米材料,尤其是纳米催化剂MIL-53(Fe)@SiO2@NiFe2O4(1.0),在室温下表现出良好的Knoevenagel缩合催化性能,这是由于MIL-53(Fe)的Lewis酸铁位点与磁性SiO2@NiFe2O4纳米颗粒的活性位点之间的协同作用。此外,这种非均相催化剂可以轻松回收,再生测试表明它可以重复使用五次而不会显著降低其催化活性,使其经济且环保。