CO2 electroreduction to multicarbon products in strongly acidic electrolyte via synergistically modulating the local microenvironment

• Published in: Nature communications Vol. 13; no. 1; pp. 7596 - 11
• Main Authors: Ma, Zesong, Yang, Zhilong, Lai, Wenchuan, Wang, Qiyou, Qiao, Yan, Tao, Haolan, Lian, Cheng, Liu, Min, Ma, Chao, Pan, Anlian, Huang, Hongwen
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.12.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 140/133; 147/143; 639/301/299/886; 639/638/161/886; 639/638/675; Aqueous electrolytes; Carbon dioxide; Catalysts; Cations; Confinement; Electrochemistry; Electrolysis; Electrolytes; Electrowinning; Humanities and Social Sciences; Hydrogen evolution; Microenvironments; multidisciplinary; pH effects; Potassium chloride; Science; Science (multidisciplinary); Selectivity; Sulfuric acid
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-35415-x

Electrochemical CO 2 reduction to multicarbon products faces challenges of unsatisfactory selectivity, productivity, and long-term stability. Herein, we demonstrate CO 2 electroreduction in strongly acidic electrolyte (pH ≤ 1) on electrochemically reduced porous Cu nanosheets by combining the confinement effect and cation effect to synergistically modulate the local microenvironment. A Faradaic efficiency of 83.7 ± 1.4% and partial current density of 0.56 ± 0.02 A cm −2 , single-pass carbon efficiency of 54.4%, and stable electrolysis of 30 h in a flow cell are demonstrated for multicarbon products in a strongly acidic aqueous electrolyte consisting of sulfuric acid and KCl with pH ≤ 1. Mechanistically, the accumulated species (e.g., K + and OH − ) on the Helmholtz plane account for the selectivity and activity toward multicarbon products by kinetically reducing the proton coverage and thermodynamically favoring the CO 2 conversion. We find that the K + cations facilitate C-C coupling through local interaction between K + and the key intermediate *OCCO. Attaining high selectivity for CO 2 electroreduction in acid is usually difficult due to competing hydrogen evolution. Here, the authors demonstrate efficient CO 2 reduction to multicarbon products in strongly acidic medium (pH ≤ 1) on a porous Cu catalyst by combining confinement and cation effects.