Catalytic Transfer Hydrogenation Of Biomass-derived Carbonyl Compounds Using Transition Metal Composites As Catalysts

Due to the oxygen-rich nature of biomass-derived molecules,the selective removal of oxidative groups has become a major challenge in using these molecules.A variety of chemical reactions,including dehydration,hydrogenation,hydrolysis,and hydrogenolysis reactions,have become common methods for deoxidizing biomass.Among them,the hydrogenation of biomass-derived carbonyl compounds is an important link in the entire system of converting biomass to high value-added chemicals.In addition,alcohol compounds can be used not only as a hydrogen source,but also as a reaction medium,and have the advantages of low cost,safety,good operability and high selectivity,so this paper will focus on the development of alcohol as a hydrogen source to catalyze the conversion of biomass-derived carbonyl compounds.On this basis,we will design catalysts with low cost,high activity,and high cycle stability,which expect to provide a certain theoretical and experimental basis for the conversion of biomass into high value-added fuels and chemicals.The main contents are as follows:1.A simple basic zirconium carbonate?BZC?catalyst was studied for the catalytic transfer hydrogenation of biomass-derived carbonyl compounds.The catalyst has a simple preparation process,can be industrially produced on a large scale,and exhibits excellent catalytic performance at low temperatures,especially from furfural?FUR?to furfuryl alcohol?FFA?.Using this catalyst,the hydrogenation reaction of FUR was effectively performed at a low temperature?less than 100??,and an FFA yield of 98.66%was obtained even at room temperature.When the temperature reached 180?,the yield of FFA quickly reached 90.29%in 15 min.During the reaction,the in-situ diffuse reflection-infrared?ATR-IR?spectroscopy was used to monitor the functional groups of the reactants and products in real time,which provided the basis for the proposed reaction mechanism.In addition,the ATR-IR spectra and X-ray photoelectron spectroscopy?XPS?results of different catalysts show that BZC is the most acidic of all the comparative catalysts,which is consistent with the results of its best catalytic performance.On this basis,we also studied the BZC catalyst expansion reaction and the hydrogenation reaction of xylose-derived FUR,and the results show that the catalyst has potential application prospects in the hydrogenation of biomass carbonyl compounds.2.Preparation of nano-Cu/AlOOH catalyst by in-situ reduction of Cu₂?OH?₂CO₃/AlOOH,participating in the catalytic transfer hydrogenation of methyl levulinate?ML??biomass carbonyl compound?,which achieve simultaneous one-pot method for preparation of catalyst and hydrogenation of ML.It was found that Cu/AlOOH catalyst with Cu/Al molar ratio of 3/1 showed the best catalytic performance for the reaction of ML hydrogenation to valerolactone?GVL?.With the increase of reaction temperature and time,GVL will be further converted into1,4-pentanediol?1,4-PDO?.The introduction of Cu/Cu⁺changed the reaction mechanism of the reaction,not only enhanced the reactivity,but also further converted GVL to 1,4-PDO.Further characterization?for example:SEM,TEM,XPS,etc.?confirms that the catalyst is heterogeneous and has good stability,which is attributed to the stability of the zero-valent copper in the catalyst and the nanometer size of the catalyst.In addition,the catalyst also shows good universal applicability to other biomass carbonyl compounds.