Studies On Immobilized Cationic Phenyl Metalloporphyrin/Heteropolyanion Composite Catalysts On CPS Microspheres And Catalytic Oxidation Property

Simulating the structure and function of porphyrin and metalloporphyrin, all kinds ofspecial structure of metalloporphyrin compounds can be designed and produced,hydrocarbons catalytic oxidation achieved efficient and high selectivity, compelling inheterogeneous metalloporphyrin catalyst. In this paper, Synchronously Synthsizing andImmobilizing Cationic Phenyl Porphyrins on CPS Microspheres, and immobilized cationiccobalt porphyrin was obtained through a coordination reaction. On this basis, Thecombination of the cationic cobalt porphyrin with the heteropoly anions of phosphotungsticacid and phosphomolybdic acid with Keggin structure by electrostatic interaction led to theformation of the immobilized composite catalysts. and their catalytic characters wereexamined and investigated.The substitution reaction between CMCPS microspheres and p-hydroxybenzaldehyde(HBA) was carried out, and benzaldehyde as a group was introduced on the surfaces of CPSmicrospheres, obtaining BA-CPS. so that the tertiary amine-containing phenyl porphyrin(TAPP) synchronistic synthesis and immobilization on the crosslinked microspheres CPS wasrealized. Finally, TAPP was transferred meso-three(4-trimethylammoniophenyl) porphyrin(TMAPP) via quaternization reaction, namely, the microspheres TMAPP-CPS, on whichcationic phenyl porphyrin was immobilized, were prepared. In this work, the main factors asreaction temperature, the solvent polarity and the catalyst acidity on the synchronisticsynthesis and immobilization of TAPP on CPS microspheres were mainly examined, Theexperimental results show that, at110℃, use the weak acid of lactic acid as catalyst and thestronger polarity solvent of DMSO, the immobilization amount of porphyrin microsphereswill be obtained18mmol/100g after8hour. After obtaining the immobilized cationic cobalt porphyry, we prepared the cationiccobalt porphyrin through the coordination reaction. And determined the content of cobalt ionof solid catalyst. In the composite reactions, phosphotungstic acid and phosphomolybdic acidwith Keggin structures were used as reagents, respectively, and the combination of thecationic cobalt porphyrin (CoP) with the heteropoly anions by electrostatic interaction led to theformation of the immobilized composite catalysts of CoPPW-CPS and CoPPMo-CPS. Wethen characterized these immobilized cationic cobalt porphyrins and heteropoly anioncatalysts. The immobilized composite catalysts were used in the oxidation of ethylbenzene bymolecular oxygen, and their catalytic characters were investigated. The results show that theimmobilized composite catalysts possess high catalyst activity. They can transform ethylbenzene into acetophenone with high selectivity, and the yield of acetophenone after12hreaches30.1%. The catalytic activity of the immobilized composite catalysts is75%higherthan that of the immobilized cobalt porphyrin. The catalytic activity of CoPPW-CPS is higherthan that of CoPPMo-CPS. Here is an optimum amount of catalyst for the reaction, andadding excessive catalyst inhibits its activity. The composite catalysts show good recycleproperties.Finally, the immobilized composite catalysts were prepared from three kinds of cationicmetalloporphyrin(CoTMAPP-CPS、FeTMAPP-CPS and MnTMAPP-CPS), and were used inthe oxidation of cyclohexane by molecular oxygen. and main factors about the catalyticactivity were studied. The results show that the composite catalysts have higher catalyticactivity than that of CoTMAPP-CPS. The percent conversion of cyclohexane with use of in8h CoPPW-CPS can get up to44.8%. and can reuse well. In the compositions of the compositecatalysts, the heteropoly anion has no catalytic activity, The metalloporphyrin acts as thecatalyst component. However, the heteropoly anion seems to have a protective effect on themetalloporphyrin against its deactivation during the catalytic reaction. Compared the threesolid compound catalysts with different metal ions, CoPPW-CPS has the hightest catalyticactivity, FePPW-CPS is in the middle and MnPPW-CPS is the last. Therefore, immobilizingcation metal porphyrin with heteropoly anion is a new way of develop high-performance heterogeneous metalloporphyrin catalyst.