The reaction of Li with O₂ in the presence of He or Ar

The reaction of Li with O₂ in the presence of He or Ar was studied at a temperature near 150 °C for inert gas pressures between 29 and 1500 Torr. In both cases, the rate of loss of free Li atoms was linear with O₂ partial pressure between approximately 0.003 and 1.3 Torr, but had a more complex dependence on inert gas pressure. In He, the reaction probably proceeded by means of the energy transfer mechanism where the dominant intermediate was LiO₂*. The results in Ar are consistent with a reaction occurring through both the energy transfer mechanism in which LiO ₂* plays an important role and the bound intermediate complex mechanism where LiAr is the primary intermediate.