The Oxidation Reaction Of Dibenzothiophene Catalyzed By Metalloporphyrin

The oxidation of dibenzothiophene (DBT) in the simulated fuel catalyzed by environmental friendly metalloporphyrin with molecular oxygen (O2) or t-butyl hydroperoxide (TBHP) as oxidant was studied respectively in this thesis.1. A series of mono-metalloporphyrins with different substituents were synthesized, such as TPPFeCl/TPPMnCl, TClTPPFeCl/TClTPPMnCl, TNTPPFeCl/TNTPPMnCl, MNTPPFeCl and THTPPFeCl. The oxgen-bridge bis-metalloporphyrins, (TPPFe)2O, (TClTPPFe)2O and (MNTPPFe)2O were also synthesized. The structures of these compounds were characterized by UV-Vis, IR,1H-NMR and MS spectrum.2. Effects of substituents and olefins on the conversion of DBT were studied with 0.1 wt% DBT as model compound, mono-metalloporphyrins as catalysts and O2 as oxidant under the optimal reaction conditions. The results presented that the catalytic activities of mono-metalloporphyrins decreased in the order of TNTPPFeCl>MNTPPFeCl≈TClTPPFeCl> TPPFeCl>THTPPFeCl, the conversion of DBT reached 100% after 2.5 h catalyzed by TNTPPFeCl, and the DBT oxidation was influenced by olefins. What's more, the autoxidation of mono-metalloporphyrins and the reaction mechanism were studied. In addition, the catalytic oxidation of DBT was conducted with oxgen-bridge bis-metalloporphyrins/O2 to investigate the effects of substituents, reaction tempareture, oxygen pressure, amount of catalyst and reaction time on the conversion of DBT. The reaction conditions were optimized. Under the optimal conditions, the universal of reaction with other thiophene compounds was studied, and the catalytic oxidation mechanism was discussed as well.3. Effects of substituents and axial N-ligands on the conversion of DBT were investigated with 0.1 wt% DBT as model compound, mono-iron/manganese porphyrins as catalysts and TBHP as oxidant under the optimal reaction conditions. The results indicated that the catalytic activities of mono-iron/manganese porphyrins decreased in the order of TNTPPFeCl>TNTPPMnCl>TClTPPMnCl>TClTPPFeCl, the conversion of DBT increased by the addition of N-ligands. The stability of catalysts during reaction and the active species of catalysis were studied by UV-Vis. The possible reaction mechanism was proposed.