Angular distributions of desorbing N 2 in thermal N 2O decomposition on Rh(1 0 0)

Abstract

The angular distribution of desorbing N 2 was studied in the decomposition of N 2O(a) on Rh(1 0 0) at 60–140 K by means of angle-resolved temperature-programmed desorption. N 2 desorption shows two peaks at around 80 K and 110 K. At low N 2O coverage, the former collimates far from the surface normal toward the [0 0 1] direction, whereas at high coverage, the desorption sharply collimates along the surface normal. The adsorption form of N 2O and its dissociation were also examined by DFT-GGA calculations. Dissociating N 2O is proposed to be lying along the [0 0 1] direction at low coverage and to change to an upright form bonding through the terminal oxygen at high coverage.