Two-directional N2 desorption in thermal dissociation of N2O on Rh(110), Ir(110), and Pd(110) at low temperatures

Abstract

Two-directional N2 desorption was found in N2O dissociation on Rh(110), Ir(110), and Pd(110) below 160 K by angle-resolved thermal desorption. N2O(a) is mostly dissociated during heating procedures, emitting N2(g) and leaving O(a). N2 showed four desorption peaks in the temperature range of 110–200 K. One of them commonly showed a cosine distribution, whereas the others sharply collimated off the surface normal in the plane along the [001] direction. The collimation angle was about 70° on Rh(110), 65° on Ir(110), and 43°–50° on Pd(110). A high-energy-atom assisted desorption model was proposed for N2 inclined emission.