Construction And Performance Of Catalysts For The Preparation Of Renewable Aviation Fuel By Condensation-hydrogenation Of Cyclopentanone

In recent years,catalytic conversion of naturally abundant renewable biomass into fuels or high-value chemicals is an effective approach to reduce dependence on fossil energy and alleviate environmental problems.Lignocellulosic biomass has attracted the attention of researchers because of its abundant reserves.Lignocellulosic biomass can be catalytically pyrolyzed to produce furfural,which can be selectively hydrogenated to cyclopentanone.Cyclopentanone is considered ideal molecules for the preparation of high-density aviation fuel due to their special structural properties.In this paper,cyclopentanone is used as a model compound,and an efficient catalyst is constructed for its self-condensation reaction and subsequent hydrodeoxygenation reaction.The main research contents are as follows:（1）A series of metal oxide catalysts with different physicochemical properties were prepared by precipitation method.The physicochemical properties and structural characteristics of the catalyst were explored by CO₂-TPD,XRD,N₂ adsorption-desorption,SEM,HRTEM,XPS and other characterization methods,and the catalytic performance of the catalyst in the self-condensation reaction of cyclopentanone was evaluated.The research shows that the rare earth metal oxide La₂O₃ has the highest catalytic activity.Under the optimal reaction conditions（140°C,4 h）,the yields of dimer and trimer are 70.0%and 10.0%,respectively,which may be attributed to its abundant oxygen vacancies and basic active sites.（2）A series of M/La₂O₃（M=Fe,Cu,Ni,Co）supported metal catalysts were prepared with La₂O₃ as carrier.The physicochemical properties and structural characteristics of the catalysts were explored by means of H₂-TPR,XRD,N₂adsorption-desorption,NH₃-TPD,SEM,HRTEM,HAADF-STEM,XPS and other characterization methods,and the self-condensation products of cyclopentanone were investigated.Catalytic performance for the hydrodeoxygenation reaction of（2-cyclopentylidenecyclopentanone）.The research shows that 10wt%Co/La₂O₃ has relatively high hydrodeoxygenation activity.Under the optimal reaction conditions（3MPa H₂,260℃,6 h）,the reaction raw materials are completely converted,and the target product dicyclopentane(C₁₀)The yield was 91.6%.This is due to the strong interaction between the active component Co and the support La₂O₃ in the 10wt%Co/La₂O₃ catalyst,which can expose more hydrogenation active sites,and the co-action of the highly dispersed active component Co and acid can effectively It promotes the cleavage of C=O bonds and the removal of oxygen atoms in the reactants,which is beneficial to the formation of target products.（3）In order to reduce equipment investment cost,reduce reaction energy consumption,and improve product yield,Co/La₂O₃ is preliminarily determined as an aldol condensation-hydrodeoxygenation bifunctional catalyst for the one-pot preparation of aviation fuel components by catalyzing cyclopentanone.According to the different reaction characteristics of the aldol condensation reaction and the hydrodeoxygenation reaction,the low temperature aldol condensation-high temperature hydrodeoxygenation one-pot method was used to study the performance of cyclopentanone to prepare aviation fuel components.The study showed that the use of two monofunctional catalysts to catalyze the self-condensation reaction of cyclopentanone and the hydrodeoxygenation of the condensation product dimer,respectively,resulted in a C₁₀ alkane yield of 64.1%,using a one-pot strategy to target alkanes C₁₀ and C₁₅.The yields reached 72.8%and 9.7%,respectively.Compared with the two-step method,the one-pot method not only simplifies the reaction steps,but also significantly improves the reaction effect.