LAUSR

Electrocatalytic carbon dioxide reduction reaction (CO2RR) holds significant potential to promote carbon neutrality. However, the selectivity toward multicarbon products in CO2RR is still too low to meet practical applications. Here the authors report the delicate synthesis of three kinds of Ag–Cu Janus nanostructures with {100} facets (JNS‐100) for highly selective tandem electrocatalytic reduction of CO2 to multicarbon products. By controlling the surfactant and reduction kinetics of Cu precursor, the confined growth of Cu with {100} facets on one of the six equal faces of Ag nanocubes is realized. Compared with Cu nanocubes, Ag65–Cu35 JNS‐100 demonstrates much superior selectivity for both ethylene and multicarbon products in CO2RR at less negative potentials. Density functional theory calculations reveal that the compensating electronic structure and carbon monoxide spillover in Ag65–Cu35 JNS‐100 contribute to the enhanced CO2RR performance. This study provides an effective strategy to design advanced tandem catalysts toward the extensive application of CO2RR.