NO2 decomposition on Rh clusters supported on single-walled carbon nanotubes

High-resolution photoemission spectroscopy was used to study Rh decorated single-walled C nanotubes before and after the exposure to NO2. We found that the metal adatoms form ordered nanocrystallites exhibiting a surface termination close to the (111) oriented crystal. After NO2 uptake at 200 K, the thermal evolution of the NOx adspecies indicates for the Rh nanocrystallites a catalytic behavior similar to the low index Rh surfaces. The Rh 3d5/2 line shape discloses the bonding of Rh atoms to NO2 and its fragments, whereas the oxidation of the metal/nanotubes contact is monitored by the energy shift of the C 1s peak.