Formation of CH_x species on a Ni(100) surface by the hydrogenation of carbidic carbon

We have investigated the formation of CH_x species by the reaction of p4g carbide with hydrogen on the Ni(100) surface. The CH_x species were directly detected using high resolution electron energy loss spectroscopy (HREELS). After hydrogenation of the surface carbide with 1 × 10^-7 Torr of H₂ at 313 K, two loss peaks at 2970 and 1380 cm^-1 were observed which indicates the formation of CH_x on the surface. The CH_x species undergoes decomposition at 330-370 K in UHV and in 1 × 10^-7 Torr H₂. Isotope exchange of the CH_x with D₂ is slower than the formation of CH_x from carbide by at least one order of magnitude.