N2 desorption in thermal N2O decomposition on Rh(100)

The angular distribution of desorbing N-2 was studied in the decomposition of N2O(a) on Rh(100) at 60-140 K by means of angle-resolved temperature-programmed desorption. N-2 desorption shows two main peaks at around 85 and 110 K. At low N2O coverage, the desorption at 85 K collimates far from the surface normal toward the [001] direction, whereas at high coverage, it sharply collimates along the surface normal. This N-2 formation is severely suppressed by surface oxygen. The other peak follows a cosine distribution. Adsorbed N2O is proposed to be lying along either the [001] or [010] direction at low coverage and in an upright form at high coverage.