Multi-directional N2 desorption in N2O decomposition on Rh(1 1 0)

Abstract The angular distribution of desorbing N 2 was studied in the decomposition of N 2 O(a) on Rh(1 1 0) at 50–200 K with angle-resolved thermal desorption. N 2 desorption showed five peaks at around 70 K (β 5 -N 2 ), 95 K (β 4 -N 2 ), 115 K (β 3 -N 2 ), 140 K (β 2 -N 2 ), and 160 K (β 1 -N 2 ). β 1 -N 2 yielded a cosine distribution, whereas the others involved desorption components that collimated at either 69 ± 3° or 27 ± 3° off normal into the [0 0 1] direction. The 27° component was suppressed on clean (1 × 1) facets. The 69° component is proposed to be due to decomposition of N 2 O oriented in the [0 0 1] direction.