In situ scanning tunneling microscopy of adsorbed sulfate on well-defined Pd(111) in sulfuric acid solution

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 484; no. 2; pp. 189 - 193
• Main Authors: Wan, Li-Jun, Suzuki, Takeshi, Sashikata, Kenji, Okada, Jun, Inukai, Junji, Itaya, Kingo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 17.04.2000; Elsevier Science
• Subjects: Adsorption; Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Scanning tunneling microscopy; Study of interfaces; Sulfate adlayer; Sulfate adlayer; Pd; Scanning tunneling microscopy; Electrode adsorption; Electrode electrolyte interface; Transition metal; Crystal face; Palladium; Order disorder transformation; Experimental study; Sulfates; Sulfuric acid; Cyclic voltammetry; Phase transformation; Inorganic anion; Crystal electrode; Adsorption structure; Aqueous solution; Platinoid
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/S0022-0728(00)00082-6

In situ electrochemical scanning tunneling microscopy (STM) disclosed that highly-ordered adlayers of adsorbed sulfate/bisulfate with atomic features having a (√3×√7) symmetry formed on a well-defined Pd(111) surface in 10 mM H 2SO 4 in the double layer potential range. Well-defined Pd(111) surfaces were prepared by a flame-annealing-quenching technique. High resolution STM imaging revealed the structure of water molecules in both the first and the second layers of a water-bilayer. Small reversible peaks at 0.45 V versus a reversible hydrogen electrode were found to be due to a disorder–order phase transition. The Pd(111)-(1×1) and (√3×√7) structures were observed at potentials negative and positive with respect to the small peaks, respectively.