Prompting CO ₂ Electroreduction to Ethanol by Iron Group Metal Ion Dopants Induced Multi‐sites at the Interface of SnSe/SnSe ₂ p–n Heterojunction

Abstract The development of non‐copper‐based materials for CO 2 electroreduction to ethanol with high selectivity at large current density is highly desirable, but still a great challenge. Herein, we report iron group metal ions of M 2+ (M=Fe, Co, or Ni)‐doped amorphous/crystalline SnSe/SnSe 2 nanorod/nanosheet hierarchical structures (a/c‐SnSe/SnSe 2 ) for selective CO 2 electroreduction to ethanol. Iron group metal ions doping induces multiple active sites at the interface of M 2+ ‐doped SnSe/SnSe 2 p‐n heterojunction, which strengthens *CO intermediate binding for further C−C coupling to eventual ethanol generation. As a representative, Fe 9.0% ‐a/c‐SnSe/SnSe 2 exhibits an ethanol Faradaic efficiency of 62.7 % and a partial current density of 239.0 mA cm −2 at −0.6 V in a flow cell. Moreover, it can output an ethanol Faradaic efficiency of 63.5 % and a partial current density of 201.2 mA cm −2 with a full‐cell energy efficiency of 24.1 % at 3.0 V in a membrane electrode assembly (MEA) electrolyzer. This work provides insight into non‐Cu based catalyst design for stabilizing the key intermediates for selective ethanol production from CO 2 electroreduction.