Adsorption of Oxygen on Rhodium at Low Pressures
Kinetics and Catalysis
, E-ISSN: 1608-3210
||LATTICE-GAS MODEL; ADSORBED MOLECULES; SUBSURFACE OXYGEN; DESORPTION; Rh(111); Rh(100); SURFACE; OXIDATION; LEED; AES
Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences
Adsorption and desorption of O-2 On polycrystalline Rh and Rh(100) at pressures below 10(-5) Pa and temperatures of 400 - 1600 K have been studied by thermodesorption (TD) and Auger Electron Spectroscopy (AES). The closeness of adsorption and desorption characteristics of both samples indicates a weak influence of the structure of the rhodium surface on these processes. The kinetics of adsorption is described by King's model, which takes into account the influence both of the precursor state and of the lateral interactions on oxygen adsorption. The complicated shape of the TD spectra of oxygen is related to the diffusion of adsorbed species into the bulk of the metal and to the process of formation-decomposition of surface rhodium oxide (Rh2O3).