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

The use of ZrO2 as a support material for IrOx-based catalysts in oxygen evolution reaction (OER) electrocatalysis was studied using ex-situ characterization and rotating disk electrode electrochemical testing of supported IrxZr(1-x)O2 on ZrO2 of varying sizes. The catalyst exhibited high OER mass (specific) activity (712 A center dot g(Ir)(-1)) and intrinsic activity (4.8 mA center dot cm(ESCA)(-2) ) at 1.6 V-RHE,V- attributed to IrxZr(1-x)O2 alloy formation, an interconnected network of Ir-x Zr(1-x)O2 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 H2O and desorbed O-2 species.