Ni‐Electrocatalytic CO <sub>2</sub> Reduction Toward Ethanol
Ting Wang, Xinyi Duan, Rui Bai, Haoyang Li, Qin Chen, Jian Zhang, Zhiyao Duan, Kai‐Jie Chen, Fuping Pan
Abstract
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.