A HIGH-TEMPERATURE PHOTOCHEMISTRY STUDY OF THE REACTION BETWEEN GROUND-STATE CU ATOMS AND N2O FROM 470-K TO 1340-K

The Metals-HTP (high-temperature photochemistry) technique has been adapted for studies with thermally unstable reactants, here N2O. The rate coefficients for the reaction Cu(4s 2S1/2) + N2O --> CuO + N2 from 470 to 1190 K are best fitted by k1(T) = 1.7 x 10(-10) exp(-5129 K/T) cm3 molecule-1 s-1 with 2-sigma precision limits varying from +/- 8 to +/- 18%, depending on temperature, and corresponding 2-sigma accuracy limits of +/- 22 to +/- 27%. It is shown that this expression correlates well with data on a series of other metal atom-N2O reactions. Above about 1190 K, the Arrhenius plot shows distinct upward curvature, which may be due to a contribution to the observed rates of vibrationally excited N2O in bending modes. For the entire 470-1340 K range the measurements are best described by k1(T) = 3.04 x 10(-20)T2.97 exp(-3087 K/T) cm3 molecule-1 s-1 with estimated 2-sigma accuracy limits of +/- 22 to +/- 28%.