The Adsorption and Replacement of Hydrogen on Polycrystalline Tungsten

Desorption spectra have been obtained which show that there are at least three β phases of hydrogen desorbed from a tungsten filament. The β2 phase was desorbed with second-order kinetics. The replacement of hydrogen by nitrogen and by carbon monoxide was observed, and simple replacement mechanisms are proposed for these processes and the replacement of carbon monoxide by nitrogen. When carbon was preadsorbed on the surface, the β1 phase of hydrogen and all the β phases of carbon monoxide and nitrogen were reduced, but the α phase of carbon monoxide was increased. A concept of identical and nonidentical sites is introduced to explain these results.