Study On Hydrogenation Of 5-hydroxymethylfurfural Catalyzed By Supported Ni Based Catalysts

Biomass,as the only renewable organic carbon resource on the earth,has attracted widespread attention due to its wide distribution,abundant reserves and low cost.5-Hydroxymethylfurfural（HMF）is derived from the biomass glucose unit,as a platform molecule,which can be converted to produce high value-added fine chemicals and energy materials.2,5-Dimethylfuran（DMF）,as the hydrogenation product of HMF,can be considered as promising new generation liquid fuel.However,problems like high catalyst cost,complicated preparation and harsh reaction conditions still exist in the domestic and international studies on the conversion from HMF to DMF.Therefore,in this paper,a series of nickel-based supported catalysts were designed and prepared using MFI molecular sieves to construct non-noble metal catalytic systems for the selective conversion from HMF to DMF.The main research contents include:（1）In this work,using citric acid as the reducing agent and ZSM-5 with a Si-Al MFI structure as a carrier,Ni/ZSM-5 catalysts with different nickel content were prepared by a simple solid-phase grinding synthesis method and exhibited a significant activity for the selective hydrogenolysis of HMF to produce DMF.The characterization of catalysts was tested by XRD,FT-IR,TG-DTG and N₂adsorption-desorption techniques.The effects of nickel loading ratios,reaction conditions and reaction mechanism were investigated.Under optimal experimental conditions,HMF conversion of 91.2%and DMF selectivity of 96.2%were obtained.It is found that a suitable proportion of metal sites and acidic sites on the catalyst surface are important for the selective hydrogenolysis,and 5-methylfurfural has been detected as an important intermediate product in this reaction.（2）In this study,non-noble Ni–Cu supported on MFI type titanium silicalite-1（TS-1）catalysts were prepared by citric acid decomposition and used to catalyze the hydrogenolysis from HMF to DMF.The composition and structure of the catalytic material were analyzed based on a series of modern test methods,which proved the existence of the Ni-Cu alloy structure on the catalyst surface.The reaction factors were screene and it was found that the conversion of HMF was 100%and the selectivity of DMF was 97.3%under the reaction conditions of THF at 180°C and 0.5 MPa hydrogen pressure for 7 h.The synergistic effect of Ni,Cu and TS-1 is beneficial to the selective hydrogenolysis of HMF.In addition,reusability experiments showed that the catalyst had good catalytic stability.The above work explored the preparation method of the new non-noble metal nickel-based catalytic materials,and these catalysts were used for efficient and directional selective conversion from HMF to DMF,which will provide the basis for catalytic conversion and process development of furan derivatives.