Adsorption of Thermally Activated Nitrogen

摘要

The interaction of nitrogen with a hot tungsten filament has been investigated. At pressures between 10minus;6and 10minus;3torr and for filament temperatures in the range 2050deg; to 2300deg;K, the nitrogen disappears at a rate proportional to the square root of the pressure with an apparent activation energy of 4.8 eV, half the dissociation energy of nitrogen. The experimental results have been compared with rates derived for various mechanisms of adsorption using absolute reactionhyphen;rate theory. It is shown that molecular nitrogen dissociates on the hot tungsten filament. The atoms are evaporated from a dilute surface layer and adsorb on the glass walls of the surrounding tube.