Research On The Properties Of Ka Oil Synthesized By The Catalyzed Oxidation Of Cyclohexane With Series Of Methyl-substituted Tetraphenyl Metalporphyrin

Cyclohexane oxidation is an important reaction in the industry, and the mixture ofcyclohexanol and cyclohexanone (commonly known as "KA oil") from the reaction is animportant chemical raw material. Non-catalytic oxidation reaction that has been mainlyused in industry has many disadvantages, such as low conversion rate, poor selectivity ofcyclohexanol and cyclohexanone, serious pollution to the environment, etc. Therefore, it isurgent and significant to find a new green oxidation method that can improve theconversion rate of cyclohexane and selectivity of cyclohexanol and cyclohexanone. As akind of bionic catalysts to stimulate monooxygenase P-450, metallic porphyrin, which hasspecial physiological activity, can activate molecular oxygen in mild conditions and exhibithigh activity and selectivity, has been the concern of scholars, especially the research onthe catalyzed oxidation of cyclohexane with Meso-substituted metalloporphyrins. So far, toour knowledge, there are no reports on the properties of KA oil synthesized by catalyticoxidation of cyclohexane by virtue of different methyl substituted tetraphenylmetalloporphyrins.Firstly, the Mn, Fe, Co, Cu metal complexes of tetra(m-methylphenyl)metalloporphyrins(Tm-MPP), tetra(p-methylphenyl) metalloporphyrins (Tp-MPP),tetra(3,4-dimethylphenyl) metalloporphyrins(TDMPP) were synthesized. The abovemethyl-substituted tetraphenylporphyrin Co and Cu are synthesized by “one-step” method.The complexes of Mn and Fe are synthesized by “two-step” method, namely, firstlysynthesizing series of methyl-substituted tetraphenylporphyrin, then followingcomplexation with metal salt in suitable conditions. The final products were characterizedby UV-vis and IR, and determined through solubility in cyclohexane、cyclohexanol andcyclohexanone.The synthesized metal porphyrins presented different catalytic activities when they were used to catalyze and oxidize cyclohexane. Through comparing the catalyticalproperties of different groups substituted metalloporphyrins, we concluded thatTm-MPPCo and TDMPPCo are suitable catalysts in catalytic oxidation cyclohexane.Through further investigating the factors on catalytic oxidation cyclohexane withTm-MPPCo and TDMPPCo, we got the optimal reaction conditions as follows: systempressure1.0MPa, air flow0.10-0.12m3/h, catalyst concentration4×10-6g.g-1, reactiontemperature150℃, and reaction time80min. In the above conditions, conversion rate ofcyclohexane can reach to more than8%; selectivity of cyclohexanol and cyclohexanonecan get to more than85%.The power function macro-dynamic model of catalytic oxidation of cyclohexane withTm-MPPCo and TDMPPCo is established through differential method. The reaction orderof cyclohexane disappearance is0level, the activation energy is1.28×105J/mol and8.26×10~4J/mol, respectively. The catalytic activity of TDMPPCo is higher than that ofTm-MPPCo.