Reaction of CH2 with adsorbed O on Ru(001) surface

The reaction pathways of CH2 in the presence of coadsorbed oxygen atoms on Ru(001) surface were investigated by means of temperature-programmed desorption (TPD), photoelectron spectroscopy (XPS and UPS) and work function measurements. CH2 species were produced by thermal and photoinduced dissociation of CH2I2. Preadsorbed oxygen atoms markedly stabilized CI bonds, shifted the desorption of CH2I2 to higher temperatures and reacted with CH2 formed to give formaldehyde above 200 K. Adsorbed formate was also detected in the temperature range of 300–450 K. The oxidation of surface species (CH2O, HCOO, CxHy) proceeded above 450 K, to produce CO, CO2, and H2O. Illumination of the (CH2I2+O) coadsorbed layer initiated the dissociation of CH2I2, and induced the reaction of CH2 with O slightly above 110 K.