In summary, dissolution-redeposition is the way of Cu surface reconstruction, and Cu⁺ species are the main intermediates driving this process. And the adsorption of molecules on the surface of Cu, forming copper adsorbate complexes, is the key to promoting the dissolution of Cu⁺. Among them, the formation of [CuCO]⁺ complex is the most favorable, which is independent on the exposed surface crystal plane structure of Cu. This work confirms the transient dissolution of Cu⁺ through clever experimental design, and provides theoretical guidance for future catalyst design in maintaining selectivity and activity.