Mild oxidation of ethane to acetic acid by H2O2 catalyzed by supported μ-nitrido diiron phthalocyanines

Low temperature selective transformation of light alkanes of natural gas to useful products continues to be an important challenge in chemistry and industry. mu-Nitrido diiron phthalocyanines were recently identified as powerful oxidation catalysts capable of oxidizing methane, benzene and transforming poly- and perfluorinated aromatic compounds under oxidative conditions. Herein, we have supported two mu-nitrido diiron complexes onto silica, graphite or nafion and their catalytic performance has been evaluated in the heterogeneous oxidation of ethane in water. Acetic acid was obtained with selectivity up to 71%. Turnover number up to 58 and 50-65 % product yields can be achieved. The cleavage of C-C bond also occurred and formic acid was formed as side product. In contrast to methane oxidation, no strong influence of 75 mM acid was observed in ethane oxidation. The reactivities of C-H bonds in methane, ethane and propane were very similar when the reaction was performed in water. In contrast, in diluted acidic solution, the mu-nitrido diiron phthalocyanine - H2O2 system exhibits 5 times higher activity in the oxidation of the methane C-H bond compared to the ethane C-H bond. (C) 2015 Elsevier B.V. All rights reserved.