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

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.