Research Of Liquid-phase Oxidation Of Toluene To Benzaldehyde

The Oxidation of Toluene is a very important aromatic hydrocarbon oxidation reaction,it can be oxidized to benzyl alcohol,benzaldehyde,and benzoic acid,which are useful chemical intermediates in our daily life.For the oxidation of toluene,researchers mainly focused on the development of efficient catalyst to improve the catalytic activity and reduce the impact of by-products on the environment.To solve the problems existed in the traditional method and the catalysts,the manganese and molybdenum bimetallic catalyst was prepared in the paper and it was applied to the oxidation of toluene for the first time.Furthermore,the effect of water was also systematically researched for the first time and the mechanism of the catalyst was obtained.Details of the research are as follows:(1)Discussed the impact of various reaction parameters on the oxidation of toluene and the optimum conditions were obtained by response surface method.The optimum conditions was as follows: 173.3?,3.19 h,1100m L/min,2g catalyst,2g sodium bromide and the volume ratio of solvent and toluene was 3.09,the molar yield of benzaldehyde reached 21.62%.We simply investigated the impact of acetic acid and different preparation methods of catalysts on the catalytic activity,the initiation effect of benzaldehyde was also discussed.The catalyst prepared by Sol-gel method exhibited the best catalytic performance,and the conversion of toluene and selectivity of benzaldehyde toluene did not significantly change after using 5 times.(2)Studied the effect of water on toluene oxidation and explained the mechanism of water by adding hydrogen bromide and sodium acetate into the feedstock.Within a certain range of water content,water can significantly improve the conversion of toluene and the selectivity of benzaldehyde.When the amount of water was 30 m L,the toluene conversion increased from 47.01% to 60.29% after 3h,and the maximum selectivity of benzaldehyde increased from 44.30% to 54.01% after 1.5h under certain conditions.(3)Obtained catalytic mechanism by changing the molar ratio of the two metals in the catalyst.Meanwhile,we further explained the impact of the molar ratio of the two metals on the conversion of toluene and the selectivity of benzaldehyde by XRD and FT-IR.