Synthesis, Characterization And Catalytic Properties Of In-containing MCM-41 For Baeyer-Villiger Oxidation Of Cyclohexanone

ε-caprolactone is an important organic intermediates and monomers with wide application which is mainly produced by Baeyer -Villiger oxidation of cyclohexanone. At the present time, the industrial technology to productε-caprolactone has shortcomings such as high explosive and the byproduct of carboxylic acid. Useing hydrogen peroxide as oxidant in Baeyer-Villiger oxidation is safe, economical, high atom efficient and environment friendly. So it can accord with green chemistry concept. But because of the low activity of hydrogen peroxide solution , research and development of more active and high performance catalysts become the focus of the chemical researchers of Baeyer-Villiger oxidation of cyclohexanone.In the first part of thesis, with InCl₃ as homogeneous catalyst and 30% hydrogen peroxide, process conditions of Baeyer-Villiger oxidation of cyclohexanone are studied. The effect of factors for instance solvent, hydrogen peroxide addition method, reaction time, the mole ratio of reactant, the amount of catalyst, and reaction temperature are investigated. The results show that the optimum process condition was 0.1mol cyclohexanone, 30g 1,2-dichloroethane, 0.1mol 30%H₂O₂, 2g InCl₃, with 80℃for 3h. Under this condition, the conversion of cyclohexanone was 47.68%, the yeild and selectivity ofε-caprolactone can reach 24.43% and 51.24%, respectively.At the second part, using hexadecyl trimethyl ammomium bromide(CTAB) as template and ammonia as alkali source Si-MCM-41 is synthesized by direct hydrothermal synthesis method(DHT) under low template concentration and weak alkaline medium. The structure of samples is characterized by X-ray diffraction(XRD), N₂ adsorption-desorption isotherms measurements, FT-IR spectra, Transmission Electron Microscope(TEM) and laser particle-size distribution. Calcination and crystallization process are discussed and the better crystallization conditions are confirmed.Thirdly, based on the study of Si-MCM-41, In-doping MCM-41 molecular sieves are sythesized. Effects of the method of synthesis, indium precursor, template and calcination atmosphere on the synthesis were investigated. The samples are also characterized by X-ray diffraction(XRD), N₂ adsorption-desorption isotherms measurements, FT-IR spectra, inductively coupled plasma atomic emission spectrometry(ICP-AES) and laser particle-size distribution. It has been found that using hexadecyl trimethyl ammomium hydroxide(CTAOH) as a template and InCl₃ as In precursor, In-doping MCM-41 molecular sieves can be synthesized by DHT method, which have four distinct peaks of MCM-41 molecular sieves. It is also proved that the catalyst has high load efficiency of indium and concentrated pore size distribution, which the In species enter the framework. In the end of the thesis, with H₂O₂ as oxidant, Baeyer-Villiger oxidation of cyclohexanone is catalyzed by In doping MCM-41 molecular sieve. The effect of process conditions such as solvent ,hydrogen peroxide addition method, reaction time, the mole ratio of reactant, the amount of catalyst, and reaction temperature are discussed. The results show that the catalytic activity of In doping MCM-41 molecular sieve is not high enough. The optimal condition for the reaction is 0.1mol cyclohexanone, the molar ratio of cyclohexanone and H₂O₂ is 1, the mass ratio of cyclohexanone and In-26[20] is 10%, 30g 1,2-dichloroethane, with 80℃for 20h. In the above condition, the conversion of cyclohexanone is 41.08%, the yeild and selectivity ofε-caprolactone can be reached 10.45% and 25.45%, respectively. Finally, it is proved that the catalytic activity decrease when it recycle several times. The loss of catalyst activity can be mostly attributed to leaching of In, which is the active component in MCM-41 carrier.