KINETIC-STUDY OF THE PARTIAL OXIDATION OF METHANE OVER FE2(MOO4)3 CATALYST

摘要

The product distributions for partial oxidation of methane over Fe2(MoO4)3 catalyst are compared with those for partial oxidation of methanol in the presence and absence of methane over the same catalyst under similar reaction conditions. The results suggest that CH3OH is the precursor of HCHO which is the main product of partial oxidation of methane by oxygen over Fe2(MoO4)3. The consecutive oxidation of HCHO leads to the formation of CO, the main by-product, and CO2. The presence of abundant methane improves the selectivity to HCHO. The results of kinetic studies on methane oxidation are analysed in terms of the Eley-Rideal model in which the rate-determining step is the activation of methane by the dissociatively adsorbed oxygen. The absence of C2 hydrocarbons in the products suggests that the reaction intermediate is either the surface CH3 species or the methoxide, formed from the reaction of CH, with the adsorbed oxygen. The mechanism for the formation of HCHO and CO is also discussed on the basis of the results of partial oxidation of methane and methanol.