The dissociative adsorption and recombination of CO, N2, SO, and O2 on Ni(111) has been studied by LEED, AES and TPD. The kinetic parameters were determined for O + O, N + N, S + O, Ccarbide + O recombination. All four reactions displayed second order kinetics with pre-exponential factors of 10-2 ± 1 cm2 atom·s. The activation energies were Eo+o = 440 kJ mol, EN + N = 210 kJ mol, Es+o = 310 kJ mol and Eccarbide+o = 175 kJ mol. The kinetics of the Cgraphite + O recombination were found to be first order indicating a condensed graphite phase with reaction at the phase boundary. These kinetics were further complicated due to an apparent phase transition of the adsorbed graphite at 970 K. The TPD results were used to estimate heats of adsorption. These estimates correlated with the heats of formation of bulk compounds.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry
- Surfaces, Coatings and Films
- Surfaces and Interfaces