Research On Preparation Of 2,5-Furandial Dehyde By Catalytic Oxidation Of 5-Hydroxy Methylfurfural Over Vanadium Oxide

Biomass is the most abundant renewable resource on the planet,which can be converted into liquid fuel and various fine chemicals by catalytic technology.It has great development prospects in supplementing and replacing non-renewable fossil resources.5-Hydroxymethylfurfural is an important platform compound derived from biomass,and its catalytic conversion is a key step in the efficient utilization of biomass resources.2,5-Furandialdehyde is one of the main products from the oxidation of 5-hydroxymethylfurfural,which is a very important fine chemical intermediate.In this work,a series of vanadium oxides and supported vanadium oxides were prepared.The effects of the oxidation of 5-hydroxymethylfurfural on the preparation of 2,5-furandialdehyde were systematically studied.Some meaningful results were obtained,mainly includes:(1)Vanadium pentoxide was used as the catalyst after calcination treatment,which is inexpensive and readily available,to catalyze the oxidation of 5-hydroxymethylfurfural.The effects of calcination temperature,oxidants,solvents and reaction temperature on the conversion of 5-hydroxymethylfurfural and the selectivity of the target product 2,5-furandialdehyde were investigated.The experimental results showed that the mass ratio of 5-hydroxymethylfurfural to the catalyst was 2.5,and the conversion of 5-hydroxymethylfurfural was 50.2% by using tert-butyl hydroperoxide as the oxidant and toluene as the solvent.The selectivity of 2,5-furandialdehyde was 90.0%.(2)Vanadium-phosphorus oxide catalysts with different V/P molar ratios were prepared by organic phase method,and 2,5-furandialdehyde was prepared by catalytic oxidation of 5-hydroxymethylfurfural with tert-butyl hydroperoxide as oxidant.The structure and morphology of vanadium phosphorus oxide catalysts were characterized by transmission electron microscopy,X-ray diffraction,thermogravimetric analysis,Fourier transform infrared spectroscopy,and Raman spectroscopy.The effects of vanadium phosphorus molar ratio,solvent,temperature and reaction time on the oxidation reaction were investigated.The results showed that the mass ratio of 5-hydroxymethylfurfural to the catalyst was 2.5,dimethyl sulfoxide was used as the solvent,tert-butyl hydroperoxide was used as the oxidant,and the reaction was carried out at 120 ℃ for 10 h.The yield of 2,5-furandidehyde was 83.6%.(3)A porous phosphorus-carbon-supported vanadium-phosphorus oxide catalyst with a large specific surface area was prepared by hard template method,and 2,5-furandialdehyde was prepared by oxidation of 5-hydroxymethylfurfural under atmospheric pressure in an air atmosphere.The results showed that the mass ratio of 5-hydroxymethylfurfural to the catalyst was 2.5,dimethyl sulfoxide was the solvent,air was used as the oxidant,and the reaction was carried out at 120 ℃ for 10 h.The conversion of 5-hydroxymethylfurfural was 98.2%,2,5-furandialdehyde selectivity was 97.3%.