Bimolecular reaction of N₂O with CO and the recombination of O and CO as studied in a single-pulse shock tube

The reaction between NsO and CO was studied in a single-plus shock tube over the temperature range 1320°-2280°K, in mixtures of the reactants highly diluted with Ar. In the range of temperatures 1317°-1908°K the rate constant for the bimolecular reaction, N₂O+CO→N ₂+CO₂, was found to be k₁= 1.1×10 exp(-23000/RT) cm mole-1-sec^-1. From the rates of formation of CO₂ above 1642°K, a constant for the nonradiative third-order recombination of O and CO was obtained (for the temperature range 1500°-3000°K), O+CO+Ar-CO₂+Ar, s=2.8×10 eip(+23800/Ar) cmmol-sec^-1. The large negative activation energy so deduced is shown to be in full agreement with the low value for the activation energy previously observed for CO₂ decomposition. An energy diagram was constructed on the basis of a recent CO flame study and results on the limiting high-pressure CO₂ decomposition. The mechanisms for the radiative and the three-body recombination, and the dissociation of CO₂, are discussed in terms of this energy diagram.