Carbon monoxide and carbon dioxide interaction with tantalum

• Published in: Surface science Vol. 72; no. 2; pp. 390 - 404
• Main Authors: Belov, V.D., Ustinov, Yu.K., Komar, A.P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1978
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(78)90303-5

The adsorption of carbon monoxide and carbon dioxide on tantalum and the dissolution of these gases in the adsorbent at T ⩾ 300 K have been studied. The flash-filament method (FFM) in a monopole mass-spectrometer and a field emission microscopy was used in the same apparatus. Carbon monoxide and carbon dioxide dissociate on the tantalum surface, carbon monoxide being desorbed in both cases during the flash. The desorption curves of CO reveal three different binding states: two of them (α and \ ́ gb 1) for the adsorbed particles whereas the high temperature desorption state relates to the adsorbate dissolved in the metal, For the \ ́ gb 1 state of CO the activation energy, the pre-exponential factor and the kinetic order in the kinetic equation of desorption have been estimated. They turned out to be E = 110 kcal/ mol, C = 3 × 10 12 sec −1, and ν = 1. The activation energy of diffusion for CO in tantalum and the energy of outgassing for the metal were found to be 9.4 and 49 kcal/mole, respectively.