关键词: 锰卟啉, 硅胶, 咪唑配体, 固载, 催化氧化

Abstract: One of the most interesting trends in oxidation of hydrocarbons with metalloporphyrins as the catalysts is oxidation of alkanes in Lyons system with molecular oxygen. Great achievements made in this field showed that supported metalloporphyrins possessed important application prospects. In order to enhance the stability of the catalyst and make it be used repeatedly, simple manganese tetraphenylporphyrin was successfully supported on silica gel modified with 3-chloropropyltrimethoxysilane and imidazole. This macromolecular metalloporphyrin was used as the catalyst for the first time for cyclohexane oxidation to cyclohexanol and cyclohexanone with air in the absence of additives or solvents. The reaction catalyzed by the modified silica gel-supported manganeseporphyrin still gave yield of 7.1% and selectivity above 90% to cyclohexanol and cyclohexanone for the fourth time use. The results also showed that the molar ratio of cyclohexanone to cyclohexanol was enhanced from 1.35 to 1.76 after the supported catalyst was used for the reaction. The stability of the manganeseporphyrin was obviously improved and can be easily recovered for reuse. The effect of the support on the catalytic activity in this catalysis system has been discussed.

Key words: Manganeseporphyrin, Silica gel, Ligand imidazole, Support, Catalysis oxidation