Platinum electrode, sulfate adsorption

Fig. 8. Dependence of benzene adsorption on potential at platinum electrode in solutions of sulfuric acid + sodium sulfate and sodium hydroxide + sodium sulfate with various pH values [120] ...

The adsorption of anions on solid surfaces is of considerable interest, mainly because of its effect on the kinetics of electrochemical reactions. Several in-situ techniques have been applied toward this purpose. Infrared measurements were used to identify adsorbed species, estimate anion adsorption isotherms, and to gain information on anion interaction with electrode surfaces. " Sulfuric acid anions are possibly the conunonest anion adsorbates because of their specific adsorption on metal surfaces. Depending on the metal, its surface orientation, and the concentration of anion, either sulfate or bisulfate can be specifically adsorbed on the surface. Identifying the predominant adsorbate on platinum-group metals has engendered some controversy. While STM studies show that... 

The adsorption of anions on metal electrodes has been studied in electrochemistry since the midfifties by many authors. The two main problems with these studies were the cleanliness of the electrolyte and the crystal orientation and topology of the noble-metal surfaces. At the beginning of the twenty-first century, the incorporation of in situ surface sensitive techniques became a reality among the electrochemists. The case of the specific adsorbable anions deserves special attention because their interaction with the surface can induce surface relaxation of the metal. One of the most interesting and important interfaces is the (bi)sulfate/platinum system. 

---