Graphitized Carbon-supported Pd(Au) Catalyzed The Hydrogenation Of 5-hydroxymethylfurfural

With excessive consumption of fossil fuels,the development and utilization of biomass renewable energy have attached more and more attention.2,5-dimethylfuran(DMF)possesses a higher energy density and a higher research octane number,so it is considered as a good gasoline additive.5-hydroxymethylfurfural(HMF),an important platform chemical,is derived from the dehydration of monosaccharides and can be hydrogenated into liquid biofuel DMF.Therefore,it is significant to synthesize the catalyst with efficient catalytic performance in the hydrogenation of HMF to DMF.In this thesis,using polyacrylic weak acid cation-exchanged resin(PWAC)as a material,a series of carbon supports(GC)with different graphitization degrees were prepared by controlling the carbonization temperature at 700,800,900 and 1000 ℃,then Pd/GC,Au/GC and PdAux/GC(x=1-4)catalysts were synthesized by a sodium borohydride(NaBH4)reduction method.The nitrogen adsorption-desorption isotherms,XRD,Raman,SEM,TEM,XPS characterizations were employed to analyze the physicochemical properties of catalysts and to study the influence of different graphitization degrees,noble metal and the interaction between Pd and Au.The study clearly showed that GC800 was the most proper support under mild reaction conditions,the higher selectivity to DMF was achieved over the Pd/GC800 catalysts,while the lower selectivity to DMF was obtained over the Au/GC800 catalysts,the bimetallic catalysts displayed excellent catalytic activity without any activator or acidic media,especially for PdAu4/GC800 catalyst.It was attributed to the intimate contact and intensive interaction between Pd and Au,so the dispersion of particles was improved and the content of active Pd0 species was increased.In addition,hydrogenation kinetics and the influence of varied reaction parameters on activity were investigated.