MOLECULAR BEAM STUDIES ON ADSORPTION-DESORPTION KINETICS OF CO AND H_2 ON Ni SURFACE

摘要

Adsorption-desorption kinetics of CO and H2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330KT480K and 720KT900K respectively for CO/Ni system. These results can be explained by a precursor state model. Their kinetic parameters: Eaα=14.6kJ/mol, Edx=49.3kJ/mol; Eaβ= 68.6kJ/mol, Edβ=200.6kJ/mol. It is shown that there are two adsorbed states in the low （350KT430K） and high （550KT625K） temperature range respectively for H2/Ni system. These results can be explained by a direct dissociative model. Their kinetic parameters:Edl=26.3kJ/mol, Edh=103.7kJ/mol.