Synthesis Of Functionalized Metal-Organic Frameworks And The Applications In Biofuel Preparation

With the development of society,the increasing demand for fossil energy has led to the accelerated depletion of non-renewable resources.Therefore,to develop and utilize renewable resources and change the energy consumption structure that relies heavily on fossil energy is the current urgent need As abundant and renewable biomass resource,lignocellulose has great potential for the production of high value-added chemicals and fuels.Besides,metal-organic frameworks(MOFs)have attracted researchers' interest in biomass conversion because of their unique structure and performance advantages.In this work,several classical MOFs and their functional materials were used as catalysts to investigate the conversion of biomass derivatives furfural(FF),levulinic acid(LA)and ethyl levulinate(EL)into highly value-added fine chemicals such as biofuels and their precursors.The synthetic and catalytic conditions were optimized to achieve the best experimental results.UiO-66,with the Lewis acid which is produced by the coordination unsaturated zirconium metal site,was used as a catalyst to catalyze the conversion of furfural to furfural alcohol(FAL)via transfer hydrogenation in isopropanol.FAL can be used to produce resins and aviation fuels,etc.The effects of reaction temperature and time,amount of catalyst and furfural were also investigated.Under the optimal reaction conditions,the FF can be completely converted to achieve a 97.4% yield and a 98% selectivity of FAL.In summary,UiO-66 exhibits high stability and excellent catalytic performance in this reaction.As a biomass-based platform compound,levulinic acid can be obtained from cellulose by hydrolysis and dehydration via acid catalysis.With a variety of functional groups,it has good reactivity because.Therefore,LA was used as a substrate,and the porous channel structure of Cu-BTC was used to encapsulate phosphomolybdic acid(HPM)to synthesize a catalyst to catalyze the esterification of LA and ethanol to get EL,which is a flavoring and fuel additive.When the reaction was carried out at 120 °C for 6 hours,the yield of ethyl levulinate(EL)was close to 100%.The unique structural and catalytic properties of the catalyst also make it perform well in cycle performance testing.As a biomass hydrogenation product,?-valerolactone(GVL)has broad application prospects.It can be used as a green solvent,food flavors and fuel additives,and can be further reacted to form liquid fuels.The esterification product EL was used as reactant,and the experimental conditions for the formation of GVL were continued in the ethanol system.ZIF-8,a MOF with nitrogen-containing organic ligands,was used as a precursor to obtain nitrogen-doped carbon material,and then supported ruthenium to synthesize catalyst Ru/N-C.The key factors affecting the test results such as reaction temperature and time,hydrogen pressure,catalyst and substrate amount were optimized.After reacting at 150 °C for 5 h,the yield of GVL was 92.1%.The small-scale reduction of catalytic activity of the catalyst after recycling was characterized and analyzed.