The reactions of hydrogen with nitrogen dioxide, oxygen, and mixtures of oxygen and nitric oxide

Abstract

The homogeneous gas-phase reactions of hydrogen with nitrogen dioxide, oxygen, and mixtures of oxygen and nitric oxide were studied in an adiabatic flow ractor. Measurements of reaction rates, reaction orders, and over-all activation energies were made in a nitrogen carrier gas over the temperature range of 850° to 1110°K and at a total pressure of 1 atmosphere. Measured rates are summarized below. hydrogen/nitrogen dioxide: d[H2]/dt=−k{[H2]1.4[NO2]/([NO2]+[NO])} k=1014.26 exp (−46,200/RT) cc0.4 mole−0.4 sec−1 hydrogen/oxygen: d[H2/dt=−k[H2] k=1010.71 exp (−39,500/RT) sec−1 hydrogen/oxygen + nitric oxide (1:2): d[H2]/dt=−k[H2] k=1016.47 exp (−68,600/RT) sec−1. Nitric oxide was found to accelerate the reaction of hydrogen and oxygen when added at low concentrations and to inhibit the reaction at high concentrations.