I. A study of the catalytic decomposition of nitric oxide. II. A chromatographic apparatus and technique for the analysis of nitric oxide in nitrogen. III. Kinetics and mechanism of the air oxidation of the dithionite ion (S2O4=) in aqueous solution

摘要

Part I:The study of the catalytic decomposition of nitric oxide at a concentration of 0.5% by volume in nitrogen was conducted over a packed bed in a tubular flow reactor. The packed bed was in the form of alumina pellets impregnated with 0.1% by weight of platinum oxide and 3.0% by weight of nickel oxide. Tests which were conducted at pressures of 1 to 15 atm and temperatures of 800 to 1000°F showed that the rate is second-order with respect to the nitric oxide and is retarded by the adsorption of atomic oxygen on the surface of the catalyst.Part II: In conjunction with the decomposition studies, a gas chromatographic technique for the analysis of nitric oxide at a concentration of less than 0.5% by volume in nitrogen was developed. The chromatograph column with a length of 8 ft contained silica gel and was operated in a temperature range of 65 to 85°C. Helium was used as the carrier gas, and the eluted components were measured by means of a thermal conductivity cell with dual thermistors.Part III: A study of the air oxidation of sodium dithionite in aqueous solution was made. A mechanism was proposed in which the SO2- freeradical ion was the reactive intermediate. The rate of oxidation was found to be half-order with respect to the dithionite ion and first-order with respect to molecular oxygen.