Kinetic and mechanistic study of hydroxyl ion electrosorption at the Pt(111) surface in alkaline media

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 466; no. 2; pp. 155 - 164
• Main Authors: DRAZIC, D. M, TRIPKOVIC, A. V, POPOVIC, K. D, LOVIC, J. D
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 28-05-1999; Elsevier Science
• Subjects: Adsorption; Alkaline solution; Chemistry; Electrochemistry; Exact sciences and technology; Exchange current density; Frumkin isotherm; General and physical chemistry; Linear Tafel approximation region; Pt surface; Quasi-equilibrium conditions; Study of interfaces; Alkaline solution; Linear Tafel approximation region; Pt surface; Quasi-equilibrium conditions; Frumkin isotherm; Exchange current density; Flat electrode; Hydroxides; Crystal orientation; Basic solution; Adsorption isotherm; Transition metal; Experimental study; Adsorption; Platinum; Sodium Hydroxides; Concentration effect; Kinetics; Thermodynamic properties
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/S0022-0728(99)00130-8

The adsorption of OH
− ions on the Pt(111) plane has been studied by fast cyclic voltammetry in sodium hydroxide solutions (0.03 to 1 M), under quasi-equilibrium and Tafel approximation conditions. It was shown that the OH
− ion adsorption is an electrosorption process with one electron exchanged between an OH
− ion and the platinum surface. The electrosorption process follows the Frumkin adsorption isotherm with low intensity repulsive interactions of the adsorbed species (
f=2–3). The estimated values of the standard electrochemical rate constant (
k°=5.6×10
−4 cm s
−1) and the standard exchange current density (
j
o
o=5.45×10
−2 A cm
−2) indicate a rather fast electrochemical process.