Preparation Of Furfuryl Alcohol And Furfuryl Acetone By Catalytic Conversion Of Biomass Based Furfural

With the continuous consumption of fossil energy and the destruction of global ecological environment,the development and application of renewable energy have been widely concerned by people.As an environmentally friendly and resource-rich renewable energy,biomass can be converted into a variety of biomass platform compounds,such as biomass-based furans,and further through specific catalytic reaction processes to prepare a variety of high value-added chemicals to promote the quality of biomass energy.Furfural,as an important biomass-based furan compound,can be prepared from furfuryl alcohol and furfuryl acetone by catalytic hydrogenation and condensation reaction.Furfural can be converted into furfuryl alcohol by transfer hydrogenation,which can solve the security risks brought by direct hydrogenation,and is more green and environmental protection;Furfuryl acetone can be synthesized by condensation of furfural and acetone using solid base catalyst instead of liquid base catalyst,which can avoid environmental pollution caused by liquid base and also be beneficial to the recovery of catalyst.In this paper,two heterogeneous catalysts of CuMgAl-LDH hydrotalcite nanomaterials with different element ratios and ferric hydroxyl oxide with different crystal types were designed and synthesized,which were respectively applied to furfural catalytic transfer hydrogenation to furfural alcohol and furfural and acetone condensation to furfural acetone.The specific work is as follows:1.CuMgAl-LDH precursors with different proportions of elements were prepared by coprecipidation method,and nano-Cu-supported Mg Al-LDH catalyst was prepared by one-pot in-situ reduction with isopropanol as reducing agent and hydrogen source,and furfural catalytic transfer hydrogenation was also completed to prepare furfural alcohol.The Cu_1.5Mg_1.5Al₁-LDH catalyst with the best catalytic performance was selected by changing the molar ratio of elements.Under the optimum reaction conditions,the conversion of furfural is up to 99%and the selectivity of furfuryl alcohol is 98%.Combined with different characterization methods,it was found that the content of copper,the degree of reduction and the Lewis acid site in the hydrotalcite structure had important effects on the reaction activity of the catalyst.Copper species can effectively realize the activation and transfer of hydrogen species and improve the ability of hydrogen transfer.Lewis’s acid site can selectively adsorb and activate C=O bond and promote the formation of furfuryl alcohol.In addition,the catalyst also showed good catalytic activity and selectivity for other carbonyl derivatives of biomass,and showed excellent cyclic stability.2.Different crystalline ferric hydroxyl oxide（α-FeOOH,β-Feoo H,γ-Feoo H,δ-FeOOH）and amorphous ferric hydroxyl oxide（a-FeOOH）were designed and synthesized as solid base catalysts for the condensation of furfural and acetone to furfuryl acetone.The catalytic test results showed that a-FeOOH catalyst showed the best catalytic activity for the condensation of furfural with acetone.By optimizing the reaction conditions（such as the amount of catalyst,reaction temperature and time）,the conversion rate of furfural is 99.9%and the selectivity of furfuryl acetone is 99%at 120°C for 2 h,which is obviously superior to the traditional liquid alkali.The structure information of iron hydroxyl oxide with different crystal types was investigated by various characterization methods.Among them,a-FeOOH catalyst has the highest specific surface area,small particle size and abundant Lewis’s base sites on the surface,which can optimize the adsorption and mass transfer of reactants,promote the formation of carboanion,and improve the performance of furfural acetone condensation reaction.