Direct conversion of methane to methanol and formaldehyde over a double-layered catalyst bed in the presence of steam
Abstract
Using a double-bed reactor configuration with an up-stream 1 mass% SO42–/1 mass% SrO/La2O3 catalyst to generate methyl radicals and a down-stream 1 mass% V2O5/SiO2 catalyst to stabilize the methyl radicals for reaction to form hydrolysable methoxide species, the methanol and formaldehyde space–time yields are increased up to five-fold for partial oxidation of methane in the presence of air and steam at moderate temperatures of 550–600 °C as compared with the single-bed 1 mass% V2O5/SiO2 catalyst, while little of these oxygenates are formed over a mechanically mixed catalyst bed.