First-order Reversal Curve Analysis of Phase Transitions in Electrochemical Adsorption: A New Experimental Technique Suggested by Computer Simulations

TL;DR

This paper introduces the application of the first-order reversal curve (FORC) method to analyze phase transitions in electrochemical adsorption, distinguishing between discontinuous and continuous transitions and accurately recovering equilibrium behavior.

Contribution

The study demonstrates that FORC analysis can differentiate phase transition types and recover equilibrium states from dynamic data in electrochemical systems, supported by both simulations and experimental feasibility.

Findings

FORC diagrams show negative regions for discontinuous transitions

No negative regions in FORC diagrams for continuous transitions

Experimental implementation is straightforward with existing equipment

Abstract

The first-order reversal curve (FORC) method for analysis of systems undergoing hysteresis is applied to dynamical models of electrochemical adsorption. In this setting, the method can not only differentiate between discontinuous and continuous phase transitions, but can also quite accurately recover equilibrium behavior from dynamic analysis for systems with a continuous phase transition. Discontinuous and continuous phase transitions in a two-dimensional lattice-gas model are compared using the FORC method. The FORC diagram for a discontinuous phase transition is characterized by a negative (unstable) region separating two positive (stable) regions, while such a negative region does not exist for continuous phase transitions. Experimental data for FORC analysis could easily be obtained by simple reprogramming of a potentiostat designed for cyclic-voltammetry experiments.