The Study On Selective Catalysis Of Tetrahydrofurfuryl Alcohol To 1,5-pentanediol Over Pt-based Catalysts

Nowadays energy crisis,climate change and environmental issues have aroused interest in developing renewable resources.Biomass has the advantages of wide distribution,large reserves,and environmental friendliness.It is currently one of the most promising new energy sources that can replace fossil energy.Therefore,it is of great significance to obtain liquid fuel and high value-added chemicals from biomass.Furfural is one of the top value-added chemicals produced by hydrolysis of hemi-cellulose,which has achieved industrial production.THFA can not only be used as green solvent for fats and resin,but also as important starting materials for compounding polyols.Among which,1,5-Pe D is of outmost important in the production of and nowadays has many applications in our society.1,5-Pe D serves as monomers in the fabrication of polymers.It was also widely employed in many fields,such as:cosmetic industry,foodstuff science and bioscience.Therefore,the preparation of 1,5-pentanediol from biomass-based tetrahydrofurfuryl alcohol has a very high prospect in application and high value in industrial.In this paper,catalysts has been screen for the hydrogenolysis of THFA to 1,5-Pe D.We designed and prepared a series of advantageous Pt/WO₃@Si O₂catalysts.Here,an embedded structure of WO₃@Si O₂support was rationally synthesized by employing a facile strategy of modified sol-gel.The structure-activity relationship and reaction mechanism catalyzed by the above catalysts were systematically studied.The main research scope was carried out as following:1.Screening of the catalysts for the hydrogenolysis of THFA to 1,5-Pe D,including oxides support and composite oxides support.And subsequently was loaded with 5.0 wt%Pt by wet impregnation.Oxides（Mo O₃,Al₂O₃,Ni O,WO₃,Cu O and Fe O_x）with different properties were selected as oxides support.Catalyst Pt/WO₃showed best catalytic performances through test.Then catalyst with composite oxides support（WO₃@Ti O₂、WO₃@Si O₂、WO₃@Zr O₂and WO₃@C）were tested in hydrogenolysis of THFA to 1,5-Pe D,and catalyst Pt/WO₃@Si O₂showed best catalytic performances.2.The effects of reaction parameters were investigated on the catalytic performances,including W/Si molar ratio,reaction time,reaction temperature and catalyst reusability.And the optimized molar ratio of W/Si,reaction time and reaction temperature were 0.8:1,36 h and 220℃,respectively.As consequence,the characterization results suggested that the Br?nsted acid sites with proper acid amounts played an important role in controlling the selective ring-opening of THFA cyclic ether towards 1,5-Pe D.3.The reduction temperature was found had a profound impact on the catalytic properties of Pt/WO₃@Si O2 catalyst.And the The high THFA conversion of 41.1%and 1,5-Pe D selectivity of 85.9%were achieved under the optimized reduction temperature 150℃.The binary mixture catalyst,comprising of WO₃@Si O2 and Pt/Si O2,positively revealed remarkable catalytic performance.Based on these evidences,it was reasonable to speculate that WO₃phase transformed into Hx WO₃phase,corresponding to the W5+species in the presence of hydrogen atmosphere,which was closely connected with the excellent catalytic activity of Pt/WO₃@Si O2 catalyst in the ring-opening of THFA cyclic ether.