The decomposition of NO2 on Rh(111): product NO velocity and angular intensity distributions

The velocity and angular distributions of NO produced from the decompositio n of NO2 on Rh(111) under both reducing and oxidizing conditions have been measured at surface temperatures between 500 K and 1000 K. When a concurren t H-2 beam is used, which keeps the surface free of oxygen, the NO product has much more translational energy than expected for equilibration at the s urface temperature, but is dependent on T-s. There is total energy scaling; the translational energy is independent of final angle. A small amount of N-2 is also produced. When the H-2 beam is turned off, oxygen builds up on the surface. Under this oxidizing condition, the NO product has an almost M axwell-Boltzmann velocity distribution at the surface temperature. (C) 1999 Elsevier Science B.V. All rights reserved.