Unveiling the effect of chloride on the surface modification of Cu(111)

Electrochemical oxidation-reduction processes in the presence of anions have been widely explored for surface preparation of tailor-made copper catalysts. Nevertheless, the role of the anion and which sites geometries induce remains elusive. To address this uncertainty, we have assessed the effect of chloride on the surface modification of a well-defined Cu(111) single crystalline electrode using a potential-pulse technique. The morphology analysis revealed the formation of shape hexagonal microstructures homogeneously distributed on the single-facet surface. This shape was nearly similar to a (310) particle growing along the direction of the (111) orientation. Herein, we provide experimental insights supporting the idea that chloride induces the formation of n(100)x(110) domains, whereas the crystal-substrate orientation determines the growth direction of the new crystallographic phase. The present work offers a straightforward approach that enables precise control over the modification of highly ordered surfaces. This strategy is relevant for rationally assessing anion effects on the formation of distinct site geometries.