Connecting Oxide Nucleation and Growth to Oxygen Diffusion Energetics on Stepped Cu(011) Surfaces: An Experimental and Theoretical Study

MT Curnan and CM Andolina and M Li and Q Zhu and H Chi and WA Saidi and JC Yang, JOURNAL OF PHYSICAL CHEMISTRY C, 123, 452-463 (2019).

DOI: 10.1021/acs.jpcc.8b08944

Current fundamental understanding of the reaction mechanisms controlling Cu oxidation encompasses early-stage chemisorption and O surface diffusion, as well as later-stage Cu oxide nano-island nucleation and growth. This understanding cannot broadly predict preferential Cu oxide formation on competing surface defects. Improving understanding on how to control preferential oxide formation can lead to more effective corrosion mitigation and Cu/Cu2O catalyst optimization strategies. Computational methods, such as density functional theory and reactive force field molecular mechanics, linked by a multiscale approach can calculate early-stage O adsorption and diffusion energetics on simulated structures comparable to experimental surface defects. Experimental methods, like environmental transmission electron microscopy, can characterize later-stage preferential Cu oxide formation on competing surface defects. This study aspires to illustrate consistency between early- and later-stage oxidation properties, finding whether computationally modeled differences in O diffusion energetics can be used to explain experimentally observable oxide formation preferences along Cu(011) stepped defects. Upon determining which energetics can be applied to reconcile experimental and computational results, edge-to- edge O diffusion mechanisms are found to contribute to oxide island formation over edge-to-terrace mechanisms. Further analysis determines which arrangements of stepped defects can lead to selective oxidation on competing adjacent stepped defects, reviewing the corners formed by these defects to characterize experimental outcomes.

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