CO dissociation and recombination reactions on Ni(100)

The kinetics of atomic carbon and oxygen buildup on a Ni(1OO) surface exposed to carbon monoxide at high temperatures have been investigated by Auger electron spectroscopy. The experimental data, taken at different sample temperatures (453 ≤ T ≤ 573 K) and at different CO partial pressures (3x10^-7 ≤ PCO ≤ 3x10^-6 mbar) allowed the identification of the CO dissociation mechanism. By fitting the experimental data with a set of rate equations describing CO dissociation, CO reduction of surface oxygen, and C and O recombination, we have been able to determine the pre-exponential factors and the activation energies of these processes.