Nickeltetracarbonyl formation on non-equilibrium Ni surfaces

The subject of this investigaton was the kinetics of Ni volatilization in form of nickeltetracarbonyl (Ni(CO)4) during the interaction of CO gas with a Ni foil at room temperature (or slightly above). A trap-decomposition technique on an auxiliary Rh surface and posterior Auger Spectroscopy were used for the product analyisis. The presence of a high step site density (kinks ) on an intentionally roughened Ni surface was found to cause a strong rate enhancement CO pressure as low as ~ 5 x 10-8 mb turned out to be sufficient for the reaction t0 occur. However a wel-annealead equilibrium Ni surface remained inactive in Ni{C0}4 formation under these conditions. A reaction model is presented by taking into account the present-day knowledge about Ni.subcarbonyl intermediate formation.