Systematic Investigation of Iridium-Based Bimetallic Thin Film Catalysts for the Oxygen Evolution Reaction in Acidic Media Authors

Alaina L. Strickler, Raul A. Flores, Laurie A. King, Jens K. Nørskov, Michal Bajdich, Thomas F. Jaramillo
Year of publication: 
ACS Applied Materials and Interfaces

Multi-metallic Ir-based systems offer significant opportunities for enhanced oxygen evolution electrocatalysis by modifying electronic and geometric properties of the active catalyst. Herein, a systematic investigation of bimetallic Ir-based thin films was performed to identify activity and stability trends across material systems for the oxygen evolution reaction (OER) in acidic media. Electron beam evaporation was used to co-deposit metallic films of Ir, IrSn2, IrCr, IrTi, and IrNi. The electrocatalytic activity of the electrochemically oxidized alloys was found to increase in the order of IrTi < IrSn2 < Ir ~ IrNi < IrCr, with the IrCr system demonstrating two times the catalytic activity of Ir at 1.65 V vs. RHE. Density functional theory calculations suggest that this enhancement is due to Cr active sites that have improved oxygen binding energetics compared to pure Iroxide. This work identifies Ir-Cr as a promising new catalyst system that facilitates reduced precious metal loadings for acid-based OER catalysis. Computational data available at

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