Direct Spectroscopic Observation of Cyanide-Induced Restructuring of Pt at the Solid–Liquid Interface

Obtaining insight into surface restructuring induced by adsorbates is essential for understanding surface (electro)chemical reactions and for better design of functional materials. Here, the microscopic restructuring of Pt(111) upon adsorption of 1,4-phenylene diisocyanide (PDI) at the solid–liquid interface is reported. With in situ vibrational sum-frequency generation spectroscopy supported by ex situ scanning tunneling microscopy studies, the surface-roughening process is followed in real-time by observing the vibrational signal of on-top-bound cyanide as a probe of the local coordination of the adsorption site. These studies show that PDI adsorbs initially on regular Pt(111) surface sites, which are transformed into low-coordinated sites with increasing exposure time. The low-coordinated sites are formed because of PDI-induced extraction of Pt atoms.