Study On Catalytic Performance Of Metal Tetraphenylporphyrins Immobilized On Graphene Oxide

Biomimetic catalysis is a meaningful research topics.Researchers used metalloporphyrins to mimic cytochrome P-450 monooxygenase.However,it is difficult to reuse the metal porphyrins in catalytic reaction,because the metal porphyrins will be damaged in homogeneous catalysis system.Therefore,seeking a green and efficient to immobilized metal tetraphenyporphyrins become the focus of research.In this study,the cytochrome P-450 enzyme was simulated using an grapheme oxide as a support for immobilizing metal tetraphenylporphyrin and forming a biomimetic catalyst.The graphene oxide with special ? electron structure.Large special surface was used as supported for immobilizing metal tetraphenylporphyrin via ?-? interaction.The immobilized material of M TPPCl/GO for oxygen oxidation of cyclohexane were investigated.The main contents in this work are as follows:1.The research progress of metal porphyrins,graphene oxide,and catalytic oxidation of cyclohexane is introduced.2.Graphene oxide(GO),tetraphenylporphyrin(TPP),metal tetraphenylporphyrin(M TPPCl)and GO-supported M TPPCl via ?-?interaction were prepared based on reference literatures.3.The catalysts materials were characterized by Ultraviolet spectroscopy(UV-Vis),Fourier Transform Infrared Spectrometry(FT-IR),Specific surface area analyzers(BET),Scanning electron microscope(SEM),Thermogravimetric analysis(TG)and X-ray photoelectron spectroscopy(XPS).and by this way,the structure and thermostability of catalyst materials are confirmed.4.The optimum reaction conditions for cyclohexane oxidation over M TPPCl/GO were explored and determined in single factor variable method.Subsequently,the catalytic performances of immobilized catalyst materials reused in the optimum reaction conditions were also investigated,and compared with those from M TPPCl,and then the relationships between catalytic performance and their structure were explored.5.The experiment results show that the catalytic activities of M TPPCl were improved by graphene oxide.The yields of ketone and alcohol in cyclohexane oxidation over Co TPPCl/GO,Fe TPPCl/GO and Mn TPP Cl/GO,in comparision with those obtained from the correspongding M TPPCl,increased 3.1%,3%and 1.9%,respectively.The catalyst materials can be reused six times for the cyclohexane oxidation,and the averaged catalytic activity remained higher than those of the corresponding M TPPCl.The size order for the catalytic performance is Co TPPCl/GO>Fe TPPCl/GO>Mn TPP Cl/GO.6.According to the experimental results and relevant references,a possible mechanism for the catalytic oxidation of cyclohexane over the supported material is proposed as a free radical reaction...