Catalytic Oxidation Of Cumene With Oxygen To Cumene Peroxide By Multi-metal Composite

The cumene hydroperoxide（CHP）,which is produced by liquid phase oxidation of cumene,is an important intermediate for the production of phenol in the chemical industry.Cumene hydroperoxide is also very important in the production of polymer materials,fine chemicals and organic synthesis.Industrially,the reaction process usually uses the homogeneous alkali catalyst,and a small amount of CHP is added as an initiator.Longer induce period,poorer safety and more by-products exist in the process,the environmental pollution,equipment corrosion and product separation are caused by the generated waste liquid of the process.Therefore,the development of heterogeneous catalysts at low temperatures and atmosphere pressures has a practical significance.In this thesis,the copper-based multi-component composite metal catalysts were prepared and applied to the reaction of liquid phase oxidation of cumene to cumene peroxide.The main research contents were as follows:1.The CuO-MnO₂-TiO₂ternary composite oxide was prepared by coprecipitation-ultrasonic assisted method,which was characterized by XRD,SEM,EDS,N₂adsorption and desorption,XPS and other techniques.CuO-MnO₂-TiO₂has high catalytic activity in the liquid phase oxidation of cumene to cumene hydroperoxide.The optimal reaction conditions was that the molar ratio of CuO/MnO₂/TiO₂is 3/1/1.33,feed ratio is 7.5 mg/ml（catalyst/cumene）,reaction temperature is 85℃,reaction time is 7 h and oxygen flow rate is 15 ml/min.Under the conditions,the conversion of cumene is 56.7%and the selectivity of CHP is 66.6%.Gas chromatography-mass spectrometry analysis showed that the main products are cumene hydroperoxide（CHP）,2-phenyl-2-propanol（CA）and acetophenone（AP）.2.CuO-ZnO-TiO₂ternary composite oxides with different composition were prepared by coprecipitation-ultrasonic assisted method.XRD,SEM,EDS,N₂adsorption and desorption,XPS were used to characterize the performance of the catalyst.The liquid phase oxidation of cumene to cumene hydroperoxide catalyzed by CuO-ZnO-TiO₂was studied.CuO-ZnO-TiO₂has high conversion rate,selectivity and stability in the liquid phase oxidation of cumene to cumene hydroperoxide.The optimal reaction conditions were that the molar ratio of CuO-ZnO-TiO₂is 3/1/1.33,the feed ratio is 7.5 mg/ml（catalyst/cumene）,the reaction temperature is 85℃,the reaction time is 7 h and the oxygen flow rate is 15 ml/min.Under the conditions,the conversion of cumene is 37.2%and the selectivity of CHP was 94.5%.3.Ca₄Cu_xAl-LDHs composite catalyst was prepared by coprecipitation method.The catalyst was characterized by XRD,SEM,EDS and FT-IR.The activity of Ca₄Cu_xAl-LDHs on the cumene liquid phase oxidation to cumene hydroperoxide was investigated.The optimum reaction conditions are as follows:the molar ratio of Ca/Cu/Al in Ca₄Cu_0.5Al-LDHs is 4/0.5/1,a feed ratio of 7.5 mg/ml（catalyst/cumene）,the reaction temperature is 85℃,the reaction time is 7 h and the oxygen flow rate is15 ml/min.The conversion of cumene is 34.5%and the selectivity of CHP was 86.9%.