Direct Experimental Evidence of Transient Au δ+ Oxide in Au Electrooxidation - Jesús Redondo; Ane Etxebarria; Pankaj Kumar Samal; Llorenç Albons; Roser Fernandez Climent; Sabine Auras; Břetislav Šmíd; Xiaohui Ju; Peter Matvija; Frederik Schiller; Martin Setvín; Josef Mysliveček; et al. (Journal of the American Chemical Society, 2026)