Dissociative sticking of CH4 on Ru(0001)

In this study the ${\mathrm{CH}}_{\mathrm{4}}$ dissociation probability on Ru(0001) is found for various translational and vibrational energies. The absolute sticking values are determined from King and Wells experiments and carbon uptake curves. The carbon amount is determined from the recombination signal of carbon with oxygen obtained after the beam exposure when heating in an oxygen atmosphere. The measured sticking coefficient of ${\mathrm{CH}}_{\mathrm{4}}$ is strongly enhanced both by increasing the translational and the vibrational energy of the ${\mathrm{CH}}_{\mathrm{4}}$ molecule. A model is applied to the data and an estimate of the thermal activation energy for ${\mathrm{CH}}_{\mathrm{4}}$ dissociation is found to be in good agreement with previous bulb experiments.