Langmuir, Vol.21, No.21, 9529-9536, 2005
Kinetics and dynamics of N(2b)formation in a steady-state N2O+COreaction on Pd(110)
The N2O decomposition kinetics and the product (N-2 and CO2) desorption dynamics were studied in the course of a catalyzed N2O+CO reaction on Pd(110) by angle-resolved mass spectroscopy combined with cross-correlation time-of-flight techniques. The reaction proceeded steadily above 400 K, and the kinetics was switched at a critical CO/N2O pressure ratio. The ratio was about 0.03 at 450 K and reached similar to 0.08 at higher temperatures. Below it, the reaction was first order in CO, and negative orders above it. Throughout the surveyed conditions, the N-2 desorption sharply collimated along about 45 degrees off the normal toward the [001] direction. Desorbing N-2 showed translational temperatures in the range of 2000-5000 K. It is proposed that the decomposition proceeds in N2O(a) oriented along the [001] direction. On the other hand, the CO2 desorption sharply collimated along the surface normal, showing a translational temperature of about 1600 K.