Atom-resolved studies of the reaction betweenH2S and O on Ni(110)

Abstract
The reaction between H2S and preabsorbed O on Ni(110) has been studied at the atomic level by means of scanning tunneling microscopy (STM). During the reaction, the initial flat (2×1)O structure is replaced by an intermediate rough surface with many small islands and troughs, all covered with a c(2×2)S overlayer. Most surprisingly, this metastable phase converts into the thermodynamically stable (4×1)S reconstructed phase. A new mechanism to activate a surface at the atomic level is suggested.