MOLECULAR ADSORBATE-INDUCED SURFACE RECONSTRUCTION - CO/PD(110)

CO adsorption on Pd{110} has been studied using reflection-absorption infrared spectroscopy (RAIRS), low energy electron diffraction (LEED) and thermal desorption spectroscopy (TDS) over the temperature range 180 to 300 K. A unique adsorption sequence occurs involving a CO-induced reconstruction of the Pd{110} surface, transforming the surface from the bulk truncation Pd{110}(1×1) structure to a missing row Pd{110}(1×2) structure over the coverage range 0.3 to 0.75 of a monolayer, driven by the higher heat of adsorption of CO on the (1×2) Pd surface. Increasing coverage to saturation results in the lifting of the missing row structure and regeneration of the bulk truncation Pd{110}(1×1) surface. This is the first conclusive report of a substantial surface reconstruction induced by a molecular adsorbate. © 1990.