Probing the Structure of a Water-Oxidizing Anodic Iridium Oxide Catalyst using Raman Spectroscopy

Iridium Oxide with a rutile structure (IrO2) is well known as one of the best dimensionally stable water oxidizing anodes used for electrochemical H2 production. This work revealed the true nature of the active material involved in water oxidizing Iridium oxide. Contrary to traditional belief, rutile IrO2 is actually not the real water oxidizing phase. The real catalyst is better described as IrOx(OH)y(H2O)z a highly hydrous material derived from edge sharing IrO6 octahedra. Study used Raman spectroscopy and theoretical calculations to understand the structure of the material.