Ni‐Electrocatalytic CO ₂ Reduction Toward Ethanol

Abstract The electroreduction of CO ₂ offers a sustainable route to generate synthetic fuels. Cu‐based catalysts have been developed to produce value‐added C ₂₊ alcohols; however, the limited understanding of complex C−C coupling and reaction pathway hinders the development of efficient CO ₂ ‐to‐C ₂₊ alcohols catalysts. Herein, a Cu‐free, highly mesoporous NiO catalyst, derived from the microphase separation of a block copolymer, is reported, which achieves selective CO ₂ reduction toward ethanol with a Faradaic efficiency of 75.2% at −0.6 V versus RHE. The dense mesopores create a favorable local reaction environment with CO ₂ ‐rich and H ₂ O‐deficient interfaces, suppressing hydrogen evolution and maximizing catalytic activity of NiO for CO ₂ reduction. Importantly, the C ₁ ‐feeding experiments, in situ spectroscopy, and theoretical calculations consistently show that the direct coupling of *CO ₂ and *COOH is responsible for C−C bond formation on NiO, and subsequent reduction of *CO ₂ ‐COOH to ethanol is energetically facile through the *COCOH and *OC ₂ H ₅ pathway. The unconventional C−C coupling mechanism on NiO, in contrast to the *CO dimerization on Cu, is triggered by strong CO ₂ adsorption on the polarized Ni ²⁺ ‐O ²⁻ sites. The work not only demonstrates a highly selective Cu‐free Ni‐based alternative for CO ₂ ‐to‐C ₂₊ alcohols transformation but also provides a new perspective on C−C coupling toward C ₂₊ synthesis.