Preparation Of Catalysts For The Hydrogenation Of Furfural To Synthesize Cyclopentanone

Cyclopentanone（CPO）is an important chemical raw material that is widely used in pharmaceuticals,fragrances and rubber.Currently CPO is mainly derived from the adipic acid pyrolysis process,which is a complex and polluting process.The hydrogenation of furfural to CPO is a low cost and environmentally friendly route,and the core of this route lies in the development of catalysts.At present,the best performance of catalysts for hydrogenation is in the noble metal category,but precious metal resources are scarce and expensive,so the study of the preparation of non-precious metal catalysts is more promising.In this thesis,a series of catalysts for the hydrogenation of furfural to synthesise CPO were prepared using non-precious metals Cu and Ni P as the active components.The structures of these catalysts were characterised and their catalytic performance was evaluated to achieve high yields of furfural hydrogenation to produce CPO.The main contents of the paper are as follows:（1）A series of catalysts with different carriers（TiO₂,Al₂O₃,ZrO₂）,co-catalytic metals（Ni,Co,Mg）,metal loading and preparation conditions were prepared using Cu as the catalytic active component,and the relationship between different factors on the catalyst structure and catalytic performance was investigated in combination with furfural hydrogenation experiments and various characterization methods.The results showed that the Ti O₂catalyst with more moderately strong L acid on the surface was a better carrier,the co-catalytic metal Co improved the ability of the catalyst to catalyse the ring opening of the furan ring,and the catalyst had a larger specific surface area and larger pore size with a metal loading of 10%Cu+10%Co and roasting at 450℃,and the loaded metal could be completely reduced at 300℃.The 10%Cu-10%Co/TiO₂catalyst gave a CPO yield of 56.71%at a reaction temperature of 150℃,a hydrogen pressure of 1.5 MPa and a reaction time of 3 h.The stability of the catalyst decreased due to the attachment of furfural polymer on the surface,and the CPO yield decreased to 37.47%after four uses.（2）The NiP/TiO₂catalysts were prepared using NiP as the catalytic active component to address the shortcomings of the Cu Co-catalyzed furan ring opening and rearrangement.The Ni P/Ti O₂catalysts were characterized and found to form full spherical particles at a Ni:P ratio of1:3.At 20%Ni P loading,the Ni P was uniformly distributed on the surface of the Ti O₂carrier and the specific surface area was large,showing a better catalytic hydrogenation effect and a yield of CPO of72.17%,and the yield decreased to 64.53%after four uses..（3）Combining the advantages of Cu-catalyzed C=O bond hydrogenation,20%Ni P/Ti O₂was treated with Cu modification.The differences between carrier modification before Ni P/Ti O₂synthesis,modification during Ni P/Ti O₂synthesis and overall modification after Ni P/Ti O₂synthesis were examined,and the results showed that the improvement in catalytic performance could only be achieved by the overall addition of Cu after Ni P/Ti O₂synthesis.The results and characterization analysis showed that the addition of Cu improved the catalyst’s ability to hydrogenate the C=O bond in furfural and to adsorb H₂,thus improving the performance of NiP/TiO₂-catalyzed furfural hydrogenation.The yield of CPO reached 83.26%at a reaction temperature of 140℃.The catalyst was recycled four times before the yield decreased to 77.32%with a good improvement in stability.