Total harmonic distortion analysis for direct methanol fuel cell anode

In this study, total harmonic distortion (THD) analysis is put forward to illustrate nonlinear behavior of direct methanol fuel cell (DMFC) anode. THD simulations by means of different methanol oxidation kinetics as well as its experimental validation are both carried out. It is shown that the THD model adopting a three-step methanol oxidation mechanism with Kauranen–Frumkin/Temkin kinetics can be used to illustrate the THD variation for DMFC anode qualitatively. The experimental THD response at the frequency range from 0.063 Hz to 0.4 Hz is identified as the reflection of the nonlinearity variation of those kinetic steps involving intermediates in the methanol oxidation. In such a frequency domain, THD value decrease monotonously with decreasing methanol concentration, which notices its accessibility on methanol concentration detection.