Design Synthesis And Catalytic Performance Of Au-Cu/Ce-Zr-O For Selective Oxidation Of 5-Hydroxymethylfurfural

5-Hydroxymethylfurfural（5-HMF）is an important biomass platform molecule that can be selectively oxidized to produce 2,5-furandicarboxylic acid（FDCA）,which has a similar molecular structure to the petrochemical raw material terephthalic acid（PTA）and can theoretically be used as a substitute for the synthesis of polyester products,thus reducing the consumption of petrochemical energy.The more effective Au catalysts for the catalytic oxidation of 5-HMF for the synthesis of FDCA still suffer from high raw material cost and easy deactivation of the Au active component.In this paper,Au_0.7-Cu_0.3（4wt.%）/Ce_0.9Zr_0.1O₂catalysts were prepared for the catalytic oxidation of 5-HMF to synthesize FDCA,characterize the structural properties of the catalysts,investigate their performance in the catalytic reaction,investigate the conformational relationship between catalyst structure and catalytic performance,and establish a low-cost and highly stable catalytic oxidation system for the synthesis of FDCA from 5-HMF.The paper synthesized Ce-Zr-O carriers by citric acid complexation,and Au-Cu/Ce-Zr-O catalysts were prepared by depositing the active metals Au and Cu onto the surface of the carriers by urea deposition precipitation.The effects of urea dosage,urea deposition temperature,calcination temperature,deposition p H,metal（Au+Cu）loading,Au/Cu ratio and carriers on the catalytic performance were investigated in the preparation process,and the preparation conditions of the catalysts were determined.The catalysts were characterized by SEM,Raman,TEM,FT-IR,XRD and XPS,and the results showed that the catalysts had good crystallinity,Cu co-existed in the form of Cu O and Cu₂O after calcination and wrapped some Au particles on the catalyst surface,and the average particle size of the active metal particles was small.The presence of Au^δ+,Cu⁺and Ce³⁺on the catalyst surface can effectively increase the surface oxygen concentration of the catalyst.These structural features together promote the synergistic catalysis between Au and Cu bimetals,which not only gives the catalyst high catalytic activity,but also effectively reduces the catalyst cost and enhances the cycle stability of the catalyst.The prepared catalysts were used in the catalytic oxidation of 5-HMF for the synthesis of FDCA reaction,and the effects of reaction conditions such as catalyst dosage,oxygen pressure,reaction temperature,reaction time and Na OH dosage on the catalytic performance were investigated.Under the optimized reaction conditions,the conversion of 5-HMF was100%and the selectivity of FDCA was 93.6%,and after five cycles of reaction,the catalysts still showed high stability,with 100%conversion of 5-HMF and 90.8%selectivity of FDCA.