The Preparation Of Metal Phthalocyanines/MCM-41 And Their Catalytic Oxidation Reaction

Metal phthalocyanine coumpounds, whose structure are similar to metal porphyrin, can simulate the active center of cytochrome P-450 single oxygenase, which are used to catalyze the oxidation of hydrocarbon compounds. But they're easy to gather when used in a homogeneous medium, in that case as the reaction moving on their catalytic activity decreased. Using inorganic molecular sieve which have inerratic pore cannal structure as the protein shell of cytochrome P-450 to synthesize the metal phthalcyanine/molecular sieve catalyst can effectively distract phthalocyanine molecule from each other. This catalyst is wildly used because the reaction condition is mild, catalytic activity is high and easy to be separated and recycled, it has a wide development prospect in the research of catalytic materials. MCM-41 is a kind of mesoporous molecular sieves which has a secondary pore size, it can hold macromolecular active monomers such as metal phthalocyanine. It also has lager specific surface area, uniform distribution porosity and good thermal stability, so the preparation of metal phthalocyanine/MCM-41 has a good application prospect in the oxidation of aromatic compounds as a heterogeneous catalyst.The main research results of this article are as follows:(1) Tetra-substituted sulfonated metal phthalocyanine such as CoPcTs, MnPcTs, FePcTs and CuPcTs were prepared by benzene anhydride-urea method. And the MPcTs/MCM-41 catalysts were synthesized by immersion method. They were characterized by IR, UV-Vis, XRD and so on. After MPcTs were encapsulated into MCM-41,the XRD results showed that MCM-41 still kept its complete six-party ordered structures.The nitrogen adsorption data showed that the most probable aperture and the specific surface of MCM-41 were both reduced, which showed that metal phthalocyanine were indeed encapsulated into the channel of mesoporous molecular sieve MCM-41.(2) The result of the UV-Vis absorption spectra of MPcTs showed that due to the strong coordination of manganese ion, the UV-Vis absorption spectrum of MnPcTs was different from that of the others, due to the energy level transition, the B band of MnPcTs appeared two absorption peaks, the Q band had a redshift, MnPcTs wasn't easy to gather in aqueous solution, while the other three MPcTs were easy to gather.(3) When using MPcTs to catalyze the oxidation of p-cresol, we found that CoPcTs has the best catalytic effect at high concentration of p-cresol, MnPcTs has the best catalytic effect at low concentration of p-cresol. When using the MPcTs/MCM-41 to catalyze the oxidation of p-crsesol, compared to MPcTs, the turnover number of p-cresol increased, due to the pore canal of MCM-41, the reaction mainly gained p-Hydroxybenzyl methyl ether.(4) When using the FePcTs/MCM-41 to catalyze the hydroxylation reaction of phenol, the result showed that FePcTs/MCM-41 has a better catalytic effect than FePcTs, there was a reversible conversion process between the product hydroquinone and p-benzoquinone.