Catalytic oxidation of toluene with molecular oxygen over manganese tetraphenylporphyrin supported on chitosan

Catalysis by simple manganese tetraphenylporphyrin [Mn TPP] supported on chitosan [CTS] for liquid phase aerobic oxidation of toluene has been investigated. The toluene conversion depends on the reaction temperature, the air pressure and the amount of catalyst, but the selectivity for aldehyde and alcohol is little affected by these three parameters. Using the Mn TPP/CTS containing 2 mg of Mn TPP as a catalyst, the aerobic oxidation of toluene under the optimum conditions of 195 °C and 0.6 MPa produced benzaldehyde and benzyl alcohol at 96% selectivity with 5.9% conversion of toluene. The catalyst can be reused once. Chitosan played an important role in the catalytic oxidation of toluene.

Graphical abstractChitosan-supported manganese tetraphenylporphyrin was used as catalyst for the aerobic oxidation of toluene. The supported catalyst gave 5.9% toluene conversion and about 96% selectivity for aldehyde and alcohol, and a catalyst turnover number of 3.70 × 105. The supported catalyst can be efficiently reused once and showed better performance than the unsupported catalyst for toluene oxidation.Figure optionsDownload full-size imageDownload as PowerPoint slide