Study by electron spectroscopy, secondary ion emission and chemical reactivity of the adsorption modes of nitrogen monoxide and water vapour on rhenium

The adsorption of nitric oxide as well as water is characterized, on rhenium (strongly oriented parallel to (0001) plane) by both dissociative and molecular adsorption. For nitric oxide, two types of molecular states have been detected (stable till around 500 and 750 K), while for water, decomposition into oxygen (or OH) and hydrogen atoms occurs at much lower temperatures (below 300 K). Analysis of the adsorption states, using spectroscopic methods (XPS, AES, SIMS) leads to an interpretation of temperature programmed desorption spectra, based on repulsive interaction models and competitive or independent reactions, and to an extension of a previous model of the attack of transition metals by oxygen to the gasification of rhenium by these two oxygenated molecules. (Auth.)