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

Abstract

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.gIr‐1) and intrinsic activity (4.8 mA.cmECSA‐2) at 1.6 VRHE, attributed to IrxZr(1‐x)O2 alloy formation, an interconnected network of IrxZr(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 O2 bubbles 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 O2 species.