Experimental evidence of palladium dissolution in anodes for alkaline direct ethanol and formate fuel cells

Abstract

Palladium is one of the best anodic catalysts for Alkaline Direct Alcohol Fuel Cell (DAFC) applications. However, its adoption in Fuel Cells (FCs) is still limited because of the deactivation of the catalyst, which hinders the long-term performance stability of the devices. In this article, we report the results of a Fixed Energy X-Ray Absorption Voltammetry (FEXRAV) investigation of a carbon-supported palladium electrocatalyst operating in a complete alkaline direct ethanol fuel cell (DEFC). Our results show palladium dissolution unambiguously, especially at cell polarizations corresponding to high anodic stresses. We have also investigated the behaviour of Pd electrocatalyst in a direct alkaline formate fuel cell (DFFC). Data show that when using formate as a fuel, the electrode Pd loss is negligible compared to the case of DEFC.