The Synthesis And Catalytic Application In Biomass Of Silica-aluminum Based Mesoporous Organic-inorganic Hybrid Materials

Recently,mesoporous silica materials has become attractive for their promising potential applications in separation,absorption,drug delivery,catalysis etc.Mesoporous silica materials have relatively uniform pore sizes,high void volumes,high surface areas and easily functionalized surface.Functionalized mesoporous materials with organic surface groups can combine the enormous functional variation of organic chemistry with the advantages of a thermally stable and robust inorganic substrate.The metal/acid bifunctional catalysts was made by incipient-wetness impregnation method and used for hydro-process.Accordingly,the research work in the thesis focuses on biodiesel through hydroprocessing of biomass over functionalized mesoporous materials and metal/acid bifunctional catalysts.The main contents and results is as following:(1)The hydrothermal method was conducted to prepare mesoporous silica materials and periodic mesoporous organosilicas.The hydrorefining catalysts,such as Fe/MCF-26,Pt/ZSM-22,and Pt/Al2O3,were made by incipient-wetness impregnation method.The surfaces of mesoporous silica and mesoporous silica-alumina materials were modified with organoamine group by grafting method.(2)One innovative castor oil jet fuel production pathway was designed and accomplished based on the deep understanding of feedstock reactivity and catalytic properties of catalysts.It consists of a series of reactions including thermal cracking,hydrogenation/hydro-isomerization,heptanal dimerization and hydrodeoxygenation.All carbon in the fatty acid chain could be theoretically converted into bio-jet fuel during the whole chemical conversion process and the carbon selectivity in the castor oil to jet fuel process is as high as 90%.The reaction of heptanal dimerization was achieved over the functionalized mesoporous silica-alumina catalyst.The catalyst showed outstanding catalytic performance and the conversion and selectivity was 100%and 84%,respectively.(3)The hydrodeoxygenation of 2-pentyl-2-nonenal and methyl 10-undecenoate over Pt/ZSM-22 and Pt/Al2O3 hydrorefining catalysts were studied in details,which suggested that the degree of hydrodeoxygenation and isomerization increased with the rise of temperature.When the temperature higher than 350?,the conversion of deoxygenation reaction can reach 100%over the Pt/ZSM-22 and Pt/Al2O3 catalyst.In addition,the Pt/ZSM-22 catalyst exhibited higher isomerization activity as compared with the Pt/Al2O3 catalyst.(4)The study on hydrodeoxygenation of fatty acid methyl esters by efficient and low cost of Fe/MCF-26 catalyst was carried out,of which the conversion and selectivity achieved 100%and 92%,respectively.The catalyst showed outstanding catalytic performance.However,the reaction can only be stable for 8 h due to the poor stability of the catalyst.There was studies on the hydrocracking of fatty acid methyl esters over iron based bifunctional catalysts such as Fe/Al-MCF-26,Fe/ZSM-5,and Fe/ZSM-22 etc.The studies showed the isomerization of fatty acid methyl ester over the iron-based catalyst didn't achieve the desired result.