In situ reordering by iodine adsorption-desorption of extensively disordered (ion-bombarded) Pd(100) electrode surfaces

✍ Scribed by Jane A. Schimpf; Juan B. Abreu; Manuel P. Soriaga

• Book ID: 103067566
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 329 KB
• Volume: 39
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(94)e0177-p

✦ Synopsis

Previous studies have shown that the singlecrystallinity of a Pd(100) electrode surface mildly disordered by electrochemical oxidation can be reestablished if the spent surface is immersed at ambient temperatures in aqueous iodide followed by reductive desorption of the interfacial iodine . In this short note, we show that an extensively disordered (Ar t -ion-bombarded) Pd( 1110) surface can also be reordered by the iodine-chemisorption method . Multiple surface oxidation-reduction cycles on the ionbombarded electrode did not regenerate an ordered surface, but the nature and/or degree of disorder was altered to resemble an anodically oxidized surface . Reordering was attained only when multiple sequences of iodine oxidative chemisorption (deposition) and reductive desorption (stripping), at potentials close to the hydrogen evolution region, were performed . Experiments were carried out in alkaline solutions to ensure that the reordering process is driven predominantly by the strong chemisorption of iodine and not by the dissolution of Pd . Electrode-surface characterization consisted of cyclic voltammetry, low-energy electron diffraction, and Auger electron spectroscopy .