Modeling CO_2 Electrolysis on Gadolinia Doped Ceria Porous Electrode using a 1-D Macro-Homogenous Model and Linear and Non-Linear Electrochemical Impedance Spectroscopy

摘要

A 1-D semi-infinite macro-homogeneous diffusion model was used to describe the electrolysis of CO_2 on 10% gadolinia doped ceria (GDC10) porous electrodes. Mathematical models of two rate determining steps, adsorption and dissociation, were devised and incorporated into the model. Based on these models, predicted non-linear electrochemical impedance spectroscopy (NLEIS) Nyquist plots were produced of the first, second, and third harmonics. There is clear differentiation between the predicted adsorption and dissociation Nyquist plots of the second and third order harmonic responses, but not first order, suggesting there is value in using NLEIS instead of solely electrochemical impedance spectroscopy (EIS) to analyze this system.