Application And Research Of Amino Acid-based Catalysts In Cellulose And Glucose Conversion

In order to reduce the dependence on fossil fuels and reduce the environmental problems caused by fossil energy consumption,the development of clean renewable energy is receiving more and more attention.What s more,the use of renewable clean energy to replace non-renewable energy has important strategic and economic significance.Biomass resources are used as clean renewable energy due to their abundant reserves,low pollution and reproducibility.In addition,the platform compounds(glucose,5-hydroxymethylfurfural,levulinic acid,etc.)produced by biomass conversion can be used as synthetic chemicals.Furthermore,as well as fuel raw materials,it can effectively alleviate the pressure caused by the use of fossil energy.Conventional biomass conversion methods have been limited in application due to low yield,harsh reaction conditions,low selectivity and environmental pollution.The design and synthetic catalysts for the efficient conversion of biomass under mild conditions is very significance.The following work has been carried out:(1)A series of amino acid protonated ionic liquids were synthesized based on biomass amino acids for catalytic conversion of cellulose to total reducing sugar(TRS)Natural amino acids were chosen as excellent precursors for the synthesis amino acid protic ionic liquids(AAPILs)and they can be easily converted to cations and properties of functionalities incorporate into ionic liquid.Herein,we reported the study to catalyze hydrolysis of cellulose in 1-butyl-3-methylimidazolium chloride solvent by using different structure of AAPILs,which were synthesized via a one-step acid-base neutralization reaction.In addition,amino,hydroxyl and carboxyl functional groups on the AAPILs serving as catalytic domain and binding domain can promote cellulose hydrolysis.Moreover,a remarkable total reducing sugar yield of 67.1%was achieved by lysine derived ionic liquid within 1.5 h at 130 ? while the cellulose conversion was nearly 100%,which was attributed to its more catalytic sites.On the whole,AAPILs are promising catalysts for the differential conversion of inedible cellulose owing to its low cost,sustainable renewable and potential biodegradable.(2)Synthesis of a catalyst based on a metal organic framework with both Bronsted acidity and Lewis acidity for catalytic conversion of glucose to levulinic acid(LA)under mild conditions.Levulimic acid(LA)is a versatile key building block in the conversion of carbohydrates and it is an important basic chemical with varnous potential uses.MIL-100(Fe)loading with insoluble lysine functionalized phosphotungstic acid(LVS-PM2)as heterogeneous catalysts have been synthesized for the conversion of glucose to LA in water.The optimized yield of LA is obtained by using Lys-PM2 to catalyze glucose conversion is comparable to the majority of effective catalysts.The highest yield of LA(57.9%)is obtained at 150 0C for 9 h with 100 mg glucose and 25 mg Lys-PM2,since the Bronsted acidity and Lewis acidity of Lys-PM2.And the catalyst is able to recycle at least four times.It demonstrates the potential of Lys-PM2 for the conversion of biomass.(3)Amino acid functionalized heteropolyacids are immobilized on the surface of the nanosilver for catalytic conversion of microcrystalline cellulose to TRS.Herein,we reported a study to efficiently catalyze hydrolysis of cellulose in 1-butyl-3-methylimidazolium chloride([BMIM]C1)by using different recyclable amino acid functionalized phosphotungstic acid(AAPTA-Ag),.which.were synthesized via immobilizing phosphotungstic acid(PTA)on nanosilver using a redox property of PTA and then obtained by acid-base neutralization reaction of PTA on nano silver with amino acid(AA).In addition,the AA on AAPTA-Ag effectively promotes the hydrolysis of cellulose,which benefits from the synergy of amino,hydroxyl and carboxyl functional groups on the AA.Furthermore,a remarkable total reducing sugar yield of 71.3%was achieved by tyrosine derived TyrPTA-Ag within 1.5 h at 140 ? while the cellulose conversion was nearly 100%,and the catalyst cycled to the fifth time still showed good catalytic performance.The catalyst overcomes the disadvantage that the amino acid functionalized phosphotungstic acid is not recoverable,and exhibits excellent cycle performance under optimal conditions.On the whole,AA-PTA-Ag is promising catalysts for the differential conversion of inedible cellulose owing to its low cost,sustainable renewable and potential biodegradable.