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Effect of nitrogen oxides NOx on gas-phase oxidation of methane by oxygen

“…In this work, this model was supplemented with steps resulting from the formation of methanol and additions of nitrogen oxides (Table 1). As in [8,9], the rate constants for the additional steps were taken from the database of the National Institute of Standards and Technology (USA) [10,11]. After such an expansion, the kinetic model includes 115 elementary gas-phase reactions.…”

“…A kinetic model consisting of 88 elementary homogeneous reactions has been used previously [8,9] to study the reaction of oxidative coupling of methane. In this work, this model was supplemented with steps resulting from the formation of methanol and additions of nitrogen oxides (Table 1).…”

Influence of the composition of perovskites based on SrMnO3 on their catalytic properties in the oxidative coupling of methane

“…The probable mechanism of the interaction of methane with the surface of the perovskite oxide catalyst is hetero-homogeneous [14] and includes an initial stage of the formation of methyl free radicals:…”

“…The methyl radicals formed in step (3) recombine in the gas phase to form the initial product of the reaction, ethane, which is converted further into ethene and C 3 -C 4 hydrocarbons [14]. Along with reaction (3), which includes a one electron transfer and leads to the formation of higher hydrocarbons from methane, more complete oxidation may occur starting from formation of a C-O bond in a surface intermediate followed by further oxidation in the surface layer of the catalyst.…”

“…1 that the ethene/ethane ratio among the reaction products increases with increasing temperature for all catalysts. This is characteristic of the hetero-homogeneous formation of these hydrocarbons [14], although it may be partially connected with the oxidative disproportionation of ethane into ethene, the rate of which increases with increasing temperature.…”