AVS 66th International Symposium & Exhibition
    Surface Science Division Thursday Sessions
       Session SS+2D+AP+AS+OX+SE-ThA

Paper SS+2D+AP+AS+OX+SE-ThA10
Edge-Enhanced Oxygen Evolution Reactivity at Au-Supported, Ultrathin Fe2O3 Electrocatalysts

Thursday, October 24, 2019, 5:20 pm, Room A220-221

Session: Dynamics at Surfaces/Reactions and Imaging of Oxide Surfaces
Presenter: Xingyi Deng, National Energy Technology Laboratory
Authors: X. Deng, National Energy Technology Laboratory
D. Kauffman, National Energy Technology Laboratory
D.C. Sorescu, National Energy Technology Laboratory
Correspondent: Click to Email
Transition metal oxides have been emerging as promising candidates to replace the state-of-the-art IrO2 electrocatalysts for oxygen evolution reaction (OER) in alkaline electrolyte, but their key structure-property relationships are often shadowed by heterogeneities in the typical catalyst samples. To circumvent this challenge, we have combined ultrahigh vacuum surface science techniques, electrochemical measurements, and density functional theory (DFT) to study the structure-dependent activity of well-defined OER electrocatalysts. We present direct evidence that the population of hydroxylated Fe edge-site atoms correlates with the OER activity of ultrathin Fe2O3 nanostructures (~0.5 nm apparent height) grown on Au(111) substrates, and the Fe2O3/Au catalysts with a high density of edge sites can outperform an ultrathin IrOx/Au OER catalyst at moderate overpotentials. DFT calculations support the experimental results, showing more favorable OER at the edge sites along the Fe2O3/Au interface with lower predicted overpotentials resulted from beneficial modification of intermediate binding. Our study demonstrates how the combination of surface science, electrochemistry, and computational modeling can be used to identify key structure-property relationships in a well-defined electrocatalytic system .