Molecular-Scale Insights into CO2 Molecule Arrangement and Interactions on Ag(110)

Abstract Metal catalysts for CO2 conversion have been widely studied to produce useful carbon resources, and their reaction products have been reported to vary with metal species and surface facets. However, the fundamental origins of these differences remain unclear, and a detailed understanding of the relevant factors from the initial step of the reaction, adsorption, is necessary. In this study, we revealed the molecular-level adsorption structures of CO2 islands on the Ag(110) surface, which is known to be more favorable for CO2 conversion than other silver surfaces, using a scanning tunneling microscope (STM). The STM imaging and single-molecule desorption analysis indicate that the CO2 islands consist of two distinct adsorption configurations, exhibiting different desorption thresholds and behaviors. These findings suggest that molecule–surface interactions, which have been considered negligible on other facets, along with intermolecular interactions, contribute significantly to the formation and stability of CO2 islands.