Study of the Methanol Conversion into Dimethyl Ether Obtained in the Process of Biomimetic Methane Monooxidation by Hydrogen Peroxide

The monooxidation of methane into methanol was carried out on biomimetic heterogeneous catalyst – iron pentafluorotetraphenylporphyrin on Al2O3 (ImtOH), at atmospheric pressure and temperatures of 200-350°C, which resulted in liquid one-carbon compounds CH3OH (19.2%), CH2O (1.55%), CH3OCH3 (8.2%) with high selectivity and are widely used in the chemical industry. In order to establish the routes of these products formation and the mechanism for the methane conversion into them, the investigation of the methanol conversion reaction was carried out, as an intermediate compound of the methane oxidation, under identical conditions on the same catalyst.The result was only dimethyl ether with 100% selectivity. This proved that in this reaction system, methanol obtained from the methane monooxidation is converted only into dimethyl ether, and formaldehyde, in parallel with methanol, is formed from methane. The mechanisms of the elementary stages of the formation of methanol, formaldehyde and dimethyl ether on the surface of the bioimitator through the formation of an active complex (ImtOOH) are presented, in which the unity of the mechanisms of redox and acid-base catalysis traced within the framework of the principle of the bond redistribution chain (BRC), similar to enzymatic reactions.