Developing highly efficient electrochemical catalysts for carbon dioxide reduction reaction (CO2RR) provides a solution to battle global warming issues resulting from ever-increasing carbon footprint due to human activities. Copper (Cu) is known for its efficiency in CO2RR towards value-added hydrocarbons; hence its unique structural properties along with various Cu alloys have been extensively explored in the past decade. Here, we demonstrate a two-step approach to achieve intimate atomic Cu-Ag interfaces on the surface of Cu nanowires, which show greatly improved CO2RR selectivity towards methane (CH4). The specially designed Cu-Ag interfaces showed an impressive maximum Faradaic efficiency (FE) of 72% towards CH4 production at -1.17 V (vs. reversible hydrogen electrode (RHE)).