Kinetic data are presented for the partial oxidation of methane to methanol and formaldehyde by nitrous oxide catalysed by molybdenum supported on silica when steam is present in the system. The data are used as evidence to show how the selective oxidation mechanism fits into an overall reaction scheme. Moreover, in support of this selective mechanism, spectroscopic evidence is given for the formation of methyl radicals and methoxide ions on the surface. 12 references, 7 figures, 1 table.