| Furfuryl alcohol,an important biomass platform molecule has been widely used in the preparation of various high value fine chemicals.1,2-Pentanediol and 1,5-pentanediol,which could be produced from furfuryl alcohol,are of high economic value in the fields of polyester polyols,solvents,and moistures.In this thesis,a series of coppermagnesium-aluminium mixed metal oxides(MMO)derived from hydrotalcite materials were synthesized.The catalyst preparation conditions(precipitation p H,magnesium precursors,metal ratios and calcination temperatures),different promotional metals,and catalyst reduction parameters were investigated for their effects on the structure and physiochemical properties of Cu Mg Al MMO catalysts.The catalytic reactivity of synthesized catalysts in furfuryl alcohol hydrogenolysis were studied.The catalytic mechanism and structure-activity relationship for the furfuryl alcohol hydrogenolysis were also proposed.Different characterization techniques were utilized to studied the physiochemical properteies of Cu Mg Al MMO catalysts under different synthesis parameters.The results indicated that the type of magnesium precursors have significant impacts on the catalyst reactivity.Catalysts with 30 wt% Cu metal content possessed moderate metal particle size and exhibited optimum catalytic performance.The precipitation p H affected the crystallinity of the copper,When the precipitation p H of 9 was used,relatively high copper crystallinity and large grain size were obtained,which led to improved catalytic activity.The increase in calcination temperature increased the number of basic sites of the catalyst,which facilitated the adsorption and activation of furfuryl alcohol molecules.The promotional effect of five metal elements,Ce,Fe,Zn,Sn and Ni,was studied to further improve reactivity Cu Mg Al catalysts.The results indicated Ce doping could significantly increase the catalytic activity.Characterization and reactivity results for Ce Cu Mg Al catalysts suggested that the introduction of cerium could increase the number of oxygen vacancies and modulate the strength of the metal-support interaction in the catalyst,resulting in better reducibility of the catalyst and higher catalytic hydrogenolysis activity,with the 1.5 wt% Ce Cu Mg Al catalyst showing the optimum reactivity,achieving 80% conversion of furfuryl alcohol,better than the reactivity of the Cu Mg Al catalyst under the same conditions.The introduction of the appropriate amount of cerium could also increase the concentration of basic sites of the catalyst,improving the adsorption and activation of furfuryl alcohol on the catalyst,leding to higer reaction activity.This thesis also studied the effect of reduction process on the catalytic performance of Cu Mg Al and Ce Cu Mg Al catalysts.It was found that the number of basic sites in the catalysts changed with reduction temperature.The reduction temperature of 450 °C generated the highest amount of basic sites,and the corresponding Cu Mg Al catalysts were more active after reduction at 450 °C than other reduction temperatures,achieving a conversion of 66.1%.According to XPS characterization of the catalysts,the catalysts reduced at 450 °C possessed more metallic copper sites and enhanced catalytic performance.The effect of different reduction time on catalyst activity was also probed.The results showed that an increase in reduction time contributed to an increase in particle size,which was also beneficial for the hydrogenolysis reactivity of the furfuryl alcohol. |
