Catalytic Decomposition of Nitric Oxide in the Presence of Alkaline Earth Oxides

The alkaline earth oxides of barium, strontium, and calcium have been studied as catalysts for the decomposition of nitric oxide. The low work func-tion characterizing these oxides is liable to favor an electron donor catalytic process which decomposes the nitric oxide molecule. The latter was Used di-luted in hel ium and the concentration was varied between 0.5 and 2.5%. Ex-periments were carried out at, respectively, 650 ~ 750 ~ and 850 ~ After passage over the catalyst, nitric and nitrous oxides were found in the gaseous phase, as well as nitrogen and oxygen. Within the limits of concentrations used, it was found that the decomposition reaction rates of nitric and nitrous oxides are mutual ly independent. Reaction rate constants were calculated, showing that constants related to nitric oxide were at]east one ' order of magnitude higher than those related to nitrous oxide this explaining, within the limits of concentrations used, the independent behavior mentioned. The total conver-sion for nitric oxide was highest for barium oxide, attaining 80 % at 850