Synergetic catalysis of manganese porphyrin-cobalt acetate for toluene oxidation with molecular oxygen

Toluene oxidation with molecular oxygen to benzaldehyde, benzyl alcohol and benzoic acid is a very important reaction in the contemporary chemical industry.The catalyst system of Co(AcO)2/Mn(AcO)2 is widely used in commercial scale toluene oxidation with air to benzoic acid.The drawback of this process is that the yield of benzaldehyde was lower than 2%. The aerobic oxidation of toluene catalyzed by metalloporphyrins achieved 20%—30% selectivity of benzaldehyde and benzyl alcohol, however, toluene conversion in the oxidation was lower than 8%.The catalysis of manganese porphyrin-Co(OAc)2 for toluene oxidation with molecule oxygen was investigated in the absence of solvents, and toluene conversion and the yield of oxidation products were found to be significantly higher than those by separate use of cobalt acetate or manganese porphyrin.The results showed that there existed co-catalysis between metalloporphyrin and Co(OAc)2 in the toluene oxidation with molecular oxygen, and reaction time, temperature, pressure and catalysts concentration affected the synergy between metalloporphyrin and Co(OAc)2.