Nonlinear Frequency Response Analysis of the Ferrocyanide Oxidation Kinetics. Part I. A Theoretical Analysis

Abstract

In this work, a nonlinear frequency response (NLFR) analysis was used for a first time in a theoretical study of nonlinear behavior of electrochemical (EC) ferrocyanide oxidation as a simple model reaction. Analytical expressions of the first- and second-order frequency response functions (FRFs) are derived. The first-order FRF is equivalent to the EC admittance and contains information about the linear behavior of the system, whereas the second-order FRF contains additional nonlinear information. The influence of different parameters, such as the heterogeneous rate constant, solution resistance, double-layer capacitance, diffusion coefficients of the reacting species, and electrode rotation rate on the characteristics of the first- and second-order FRFs was checked and discussed. It was found that the second-order FRF is more sensitive to the changes of the studied parameters than the first-order FRF. Experimental verification of the NLFR analysis of EC ferrocyanide oxidation is presented in Part II of this work.

Electrochemical Impedance Spectroscopy and its Applications

“…Another approach using nonlinear frequency response analysis with the help of the Volterra series expansion and generalized Fourier transform was also proposed and applied to the study of methanol or ferrocyanide oxidation [666][667][668].…”

Evaluation of Electrochemical Process Improvement Using the Computer-Aided Nonlinear Frequency Response Method: Oxygen Reduction Reaction in Alkaline Media

“…This concept was initially introduced through the NFR method in chemical engineering on examples like adsorption and chemical reaction systems (Petkovska, 2001 ; Petkovska and Seidel-Morgenstern, 2013 ). In the last decade, the NFR method was further developed on electrochemical examples like direct methanol fuel cell anode oxidation kinetics (Bensmann et al, 2010 ), ferrocyanide oxidation (Panić et al, 2011 ; Vidaković-Koch et al, 2011 ), and, recently, ORR kinetics (Kandaswamy et al, 2019 ). In these previous publications, the focus was on the analysis of nonlinearities contained in the higher-order harmonics, especially the second-order harmonic.…”

Dual kinetic curves in reversible electrochemical systems

“…The current at the anodic limiting region is 1.83 mA and -1.02 mA at the cathodic region. The reason the absolute value of the cathodic current is not exactly half of the anodic limiting current is because the two species have slightly different diffusion coefficients (ferrocyanide = 6.0x10 -10 m 2 s -1 and ferricyanide = 7.0x10 -10 m 2 s -1 )[ 15 ].…”