Accelerated dissolution of iridium anode in the presence of organic compounds

Abstract

Iridium oxide is commonly used as a catalyst for the oxygen evolution reaction (OER) in various electrolysers. In this study we investigate the impact of organic compounds, such as ethanol, in the accelerated dissolution of iridium oxide, particularly in amorphous form, across a wide pH range. Our findings suggest that organic compounds produced via electrochemical reaction, including CO2 reduction, can severely compromise the stability of Ir based catalysts during OER. In situ/operando analysis reveals that this degradation is driven by aldehyde oxidation, where dual-lattice oxygen from acetate occupies the oxide lattice of Ir, leading to the collapse of the iridium oxide matrix. This observation highlights the need to find alternative anodic reactions or materials to avoid crossover induced deactivation of the anodic catalyst.