Ion-Exchanging Fabrication of Hierarchical Al-MOF based Resin Catalysts for the Tandem Reaction.

Metal-organic frameworks (MOFs) supported macroscale resin catalysts, IRA900(xOH)-MIL-101(Al)-NH2 (x means the concentration of NaOH), with spatially isolated antagonistic acid-base active sites, were successfully synthesized through a novel strategy by ion exchange and in-situ solvothermal method. The hierarchically pore system of as-prepared catalysts effectively promote the mass transfer and contaction with catalytic acitive centers during the organic reactions. Therefore, the environmentally friendly catalysts exhibit excellent superior activity and stability in one-pot deacetalization-Knoevenagel condensation reaction, and the yield by optimal IRA900(0.2OH)-MIL-101(Al)-NH2 reaches close to 99% after 5h at 110 oC. Thanks to the millimeter-sized resin carrier and robust sphere morphology, the recycle of as-prepared catalysts only require natural sedimentation. This work presents an effective strategy to bulid low-toxic acid-base catalysts by combining the advantages of ion exchange resins and functionalized MOF materials.