Evaluation of an air-breathing anion-exchange membrane fuel cell based on Pd0.9−Cu0.1/rGO anode catalyst for low ethanol sensing

Abstract

Breath alcohol analyzers (BrAAs) can utilize anion exchange membrane fuel cells (AEMFCs) as an alternative to proton exchange membrane ones, allowing non-platinum catalysts in BrAA structure. In this respect, an anode catalyst consisting of ${\mathrm{Pd}}_{0.9}-{\mathrm{Cu}}_{0.1}/\mathrm{rGO}$ is used in the AEMFC catalyst layer to sense low ethanol concentration solution in the presence of carbonate. In addition to catalyst structural analysis, the performance of the prepared AEMFC is evaluated using the electrochemical tests. Polarization curves of the air-breathing passive ethanol fuel cell show a high power density output of 189 ${\mathrm{mWcm}}^{-2}$ at 2 M of ethanol. To assess the sensitivity of the AEMFC, the polarization and V–t curves are investigated at low ethanol concentrations of 5-50 ${\mathrm{mmolL}}^{-1}$. According to the obtained results, the sensor’s highest sensitivity is achieved at 300 mV, indicating that voltage can be used for sensitivity control. In addition, the separation of the anode and cathode polarization curves shows that the anode current density increases with ethanol concentration, whereas the cathode current density remains constant. Overall, the sensitivity and repeatability evaluations represent ${\mathrm{Pd}}_{0.9}-{\mathrm{Cu}}_{0.1}/\mathrm{rGO}$ as an appropriate anode catalyst in the new generation of breath alcohol analyzers based on AEMFC.