Fig. 4. The mass spectrometry results for Fe-ferrierite.

Time dependence of the intensity of the signals of ion currents reflecting the products of the oxidation of methane by the α-oxygen formed on Fe-ferrierite during the first oxidation cycle monitored by mass spectrometry (MS). The signal with m/z = 31 relates to methanol, that with m/z = 44 links with CO₂, and that with m/z = 29 corresponds to methanol and other possible oxidation products (i.e., formaldehyde, formic acid, and dimethyl ether).