Study On Performances Of Catalytic Oxidation Of Metalloporphyrins Supported By Mesoporous Ag₂S By RSM

The research on the catalytic performance of metalloporphyrins is of great significance to guide the industrial production of important chemical raw materials?such as cyclohexanone and acetophenone?and the theoretical research of alkane C-H oxidation.At the same time,the industrial methods for the production of cyclohexanone,acetophenone and other chemical raw materials have the disadvantages of low conversion rate and not clean enough,In this study,metalloporphyrins supported on mesoporous silver sulfide?mp-Ag₂S?were used to catalyze the oxidation of cyclohexane and ethylbenzene to cyclohexanone and acetophenone,which was used to study the internal and external factors affecting the catalytic performance of metalloporphyrins,and provided a new method for the production of cyclohexanone and acetophenone.In order to improve the catalytic performance of 5,10,15,20-tetra?4-pyridyl?manganese porphyrin?Mn TPyP?and 5,10,15,20-tetra?4-pyridyl?iron porphyrin?Fe TPyP?,Mn TPyp and Fe TPyP were respectively immobilized on the Mesoporous cavity of mesoporous silver sulfide?mp-Ag₂S?through sulfur coordination,forming biomimetic catalyzer materials,Mn TPyP/mp-Ag₂S and Fe TPyP/mp-Ag₂S.Lot of Characterization methods were applied to characterize and analyze the new catalysts,and the important influence factors of the catalytic performance of cyclohexane and ethylbenzene oxidation were studied.The main contents and results of this study are as follows:1.The research progresses of metalloporphyrin,catalytic oxidation of cyclohexane and ethylbenzeneand,response surface optimization?RSM?were introduced.2.Mn TPyP,Fe TPyP and mp-Ag₂S were synthesized,and the supported catalysts Mn TPyP/mp-Ag₂S and Fe TPyP/mp-Ag₂S were prepared by axial sulfur coordination with mesoporous cavity.3.The structure,morphology and thermal stability of the catalyzer materials were characterized by ultraviolet spectrum?UV-Vis?,infrared spectrum?FT-IR?,Raman,energy dispersive spectrum?EDS?,transmission electron microscope?TEM?,specific surface analysis?BET?,thermogravimetric analys is?TG?and X-ray photoelectron spectroscopy?XPS.?4.Four factors?reaction temperature,oxygen pressure,amount of catalyst and the ratio of total surface area of Mn?Fe?TPyP to the total surface area of mp-Ag₂S?TSAR??that affect the catalytic activity of oxidizing cyclohexane?ethylbenzene?were investigated by traditional single factor optimization method?TOM?.The results show that the Supported catalyst can be used 6 times.Compared with Mn TPyP and Fe TPyP,the new catalyst has greatly improved its catalytic activity and reusability.5.The single-factor optimization results could not reflect the influence of the correlation between various important factors on catalyst activity.In order to further study the influence of the interaction between the factors on the catalytic activity of the new catalyst for the oxidation of cyclohexane and ethylbenzene,taking the above four important influenc ing factors as variables.The conversion rate?CC?of cyclohexane and ethylbenzene was used as the response value.The RSM was explored through the four-factor three-level Box-Behnken experimental design.Under the optimized control conditions of cyclohexane oxidation obtained by RSM,the conversion rate?CC?of cyclohexane oxidation catalyzed by Mn TPyP/mp-Ag₂S reached 41.10%,which was 14.80%higher than the value obtained from Tom.The conversion rate?CC?of ethyl benzene oxidation catalyzed by Fe TPyP/mp-Ag₂S under the optimized control reaction conditions of ethylbenzene oxidation obtained by RSM model reached 57.24%,which was 18.70%higher than the value obtained from Tom.This showed that the optimization of some important influenc ing factors by RSM could find the optimal catalytic oxidation reaction conditions of cyclohexane and ethylbenzene more accurately than the traditional single-factor control method.And it could obtain better catalytic results.6.According to test control groups and related literatures,it is speculated that the mechanism of substrate oxidation catalyzed by Mn TPyP/mp-Ag₂S and Fe TPyP/mp-Ag₂S may be the mechanism of free radical reaction.