Nonlinear Spectroscopy Analysis for Electrocatalytic Oxidation of Methanol on PtRu/C Surface

A new generation of electrochemical spectroscopic analysis-total harmonic distortion(THD) spectrum was used to characterize the nonlinear characteristic frequency response of methanol electrocatalytic oxidation on PtRu/C surface. By comparing the experimental and numerical results of THD spectra of methanol oxidation on Ru catalysts with different contents, this work have qualitatively investigated the feasibility of THD spectrum in methanol electrocatalytic oxidation mechanism identification and electrode performance diagnosis. The experimental results show that in the range of 0.25-1 Hz frequency domain, THD increases with the decrease of Ru content, and decreases with the decrease of methanol concentration. Compared to EIS, THD has advantages over this failure diagnosis due to its opposite tendency of experimental results. The results of numerical simulation of THD spectrum show that according to whether electrode. potential. related step exist in the oxidation of COads and different isothermal adsorption models, the mechanism of methanol oxidation based on Kauranen-Frumkin/Temkin mechanism can reproduce steady state, linear and nonlinear frequency response of methanol electrocatalytic oxidation with different Ru content on PtRu/C surface.