Catalytic Hydrogenation Of Furfural Over Cu-MOF-derived Catalysts

Furfural（FFR）,as an important biomass platform compound,can be converted into furfuryl alcohol and other important chemical products through the hydrogenation process of molecular hydrogen catalytic hydrogenation and“non-added H₂”catalytic transfer hydrogenation.In this paper,a series of catalysts modified by iron and palladium components were prepared based on Cu-MOF,and the catalytic hydrogenation of furfural was realized by adding additional molecular hydrogen or using alcohol as hydrogen donor.The main research results are as follows:（1）Fe（NO₃）₃/Cu-MOF was used as catalyst precursor to prepare catalysts in H₂and N₂atmospheres,respectively.In the preparation of Fe/Cu@C by calcination of Fe（NO₃）₃/Cu-MOF in H₂atmosphere,Fe³⁺and Cu²⁺will be reduced to Fe⁰and Cu⁰by H₂during pyrolysis and carbonization of Cu-MOF,while in the preparation of Fe₃O₄/Cu@C by calcination of Fe（NO₃）₃/Cu-MOF in N₂atmosphere,the pyrolysis carbonization of Cu-MOF is accompanied by the occurrence of carbothermic reduction reaction,which reduces Fe³⁺and Cu²⁺to Fe₃O₄and Cu⁰.With the help of Cu-MOF pyrolytic carbonization and carbon thermal reduction reaction characteristics,Fe₃O₄particles form embedded structure on the surface of carbon materials,while Cu⁰particles have carbon coating structure,which helps to limit the growth of Fe₃O₄and Cu⁰particles.Compared with Fe/Cu@C,Fe₃O₄/Cu@C showed higher activity of furfural hydrogenation.Fe₃O₄is not only beneficial to the magnetic recovery of the catalyst,but also can realize the catalytic transfer hydrogenation of furfural as the active component.In the Fe₃O₄/Cu@C catalytic furfural hydrogenation reaction system,on the one hand,the direct catalytic hydrogenation takes place with Cu⁰as the active center under the condition of additional molecular hydrogen,on the other hand,isopropanol as the solvent acts as hydrogen donor simultaneously,and the catalytic transfer hydrogenation takes place under the action of Cu⁰and Fe₃O₄.（2）Pd-Cu@C catalyst with carbon coating structure was prepared by pyrolysis and carbonization of Pd@Cu-MOF with carbon coating structure in different atmosphere.Compared with H₂atmosphere,the calcination in N₂atmosphere is more favorable to the pyrolysis carbonization of Cu-MOF and the stabilization of Cu⁰particles,and the Pd-Cu@C catalyst prepared by this method has high catalytic hydrogenation activity for furfural.The hydrogenation activity of Pd-Cu@C catalyst prepared by self-reduction to Pd⁰particles was higher than that of Pd/Cu@C catalyst prepared by impregnation method.There are direct catalytic hydrogenation with molecular hydrogen as hydrogen source and catalytic transfer hydrogenation with isopropanol as hydrogen donor in furfural catalytic hydrogenation process.