Two-directional N2 desorption in thermal dissociation of N2O on Pd(1 1 0) at low temperatures

The angular distribution of desorbing N2 was studied in the thermal decomposition of N2O(a) on Pd(1 1 0). N2O(a) was mostly decomposed during heating procedures, emitting N2(g) and leaving O(a). N2 showed four desorption peaks, β1-N2 around 150 K, β2-N2 around 134 K, β3-N2 at 123 K, and β4-N2 at 110 K. The first peak was found at high N2O exposures and the last at low exposures. Both β1-N2 and β3-N2 revealed inclined emission at +43° and −43° off the surface normal in the (0 0 1) plane, β4-N2 sharply collimated around +50° and −50°, and β2-N2 showed a cosine distribution.