The reaction pathways of CH2 in the presence of coadsorbed oxygen atoms were investigated by means of temperature-programmed desorption and high-resolution electron energy loss spectroscopy. The CH2 species was produced by the dissociation of CH2I2. Adsorbed oxygen atoms reacted with CH2 above 170 K to give formaldehyde, which desorbed from the surface after its formation. Above 340 K, the oxidation of CH2 led to the production of CO2 and H2O.