Review on the Determination of Frumkin, Langmuir, and Temkin Adsorption Isotherms at Electrode/Solution Interfaces Using the Phase-Shift Method and Correlation Constants

Abstract

This review article described the electrochemical Frumkin, Langmuir, and Temkin adsorption isotherms of over-potentially deposited hydrogen (OPD H) and deuterium (OPD D) for the cathodic H2 and D2 evolution reactions (HER, DER) at Pt, Ir, Pt-Ir alloy, Pd, Au, and Re/normal (H2O) and heavy water (D2O) solution interfaces. The Frum-kin, Langmuir, and Temkin adsorption isotherms of intermediates (OPD H, OPD D, etc.) for sequential reactions (HER, DER, etc.) at electrode/solution interfaces are determined using the phase-shift method and correlation constants, which have been suggested and developed by Chun et al. The basic procedure of the phase-shift method, the Frumkin, Lang-muir, and Temkin adsorption isotherms of OPD H and OPD D and related electrode kinetic and thermodynamic param-eters, i.e., the fractional surface coverage (0 ≤ θ ≤ 1) vs. potential (E) behavior (θ vs. E), equilibrium constant (K), interaction parameter (g), standard Gibbs energy (ΔGθ˚) of adsorption, and rate (r) of change of ΔGθ˚ with θ (0 ≤ θ ≤ 1), at the interfaces are briefly interpreted and summarized. The phase-shift method and correlation constants are useful and effective techniques to determine the Frumkin, Langmuir, and Temkin adsorption isotherms and related electrode kinetic and thermodynamic parameters (θ vs. E, K, g, ΔGθ˚, r) at electrode/solution interfaces.