Diffusion and Heterogeneous Reaction. XII. Measurements of O–O2 Diffusion as a Function of Temperature

Abstract

Steady‐state and time‐transient measurements of the decay of oxygen atoms in a cylinder with catalytic walls have been used to determine the diffusion coefficient of atomic oxygen in molecular oxygen over the temperature range 298–873°K. The resulting temperature dependence of the O–O₂ diffusion coefficient was fitted to a modified Buckingham potential with $\text{ε\hspace{0.17em}/\hspace{0.17em}k\hspace{0.17em}=\hspace{0.17em}16°}\mathrm{K}\text{, α\hspace{0.17em}=\hspace{0.17em}15,}\mathrm{and}{r}_m\text{\hspace{0.17em}=\hspace{0.17em}4.99 Å}$ . Measurements of the surface reaction rate of oxygen atoms on quartz gave a value for the recombination coefficient ${\text{γ\hspace{0.17em}=\hspace{0.17em}1.70\hspace{0.17em}×\hspace{0.17em}10}}^{\text{−4}}$ with little variation in temperature over the range studied.