Strong Metal‐Support Interactions in ZrO2‐Supported IrOx Catalyst for Efficient Oxygen Evolution Reaction

Abstract The use of ZrO 2 as a support material for IrO x ‐based catalysts in oxygen evolution reaction (OER) electrocatalysis was studied using ex‐situ characterization and rotating disk electrode electrochemical testing of supported Ir x Zr (1‐x) O 2 on ZrO 2 of varying sizes. The catalyst exhibited high OER mass (specific) activity (712 A ) and intrinsic activity (4.8 mA ) at 1.6 V RHE, attributed to Ir x Zr (1‐x) O 2 alloy formation, an interconnected network of Ir x Zr (1‐x) O 2 nanoparticles and the presence of Ir(III)/Ir(IV) species throughout the bulk. It also appears to be resistant to Ir dissolution; however, accumulation of O 2 bubbles in the catalyst microstructure and minor phase transformation of Ir(III)/Ir(IV) species during OER cause deactivation. Temperature‐programmed desorption indicated a possible link between the observed high activity and higher amounts of adsorbed H 2 O and desorbed O 2 species.