Zinc Hollow-Fiber Penetration Electrode Promotes Ampere-Level CO2 Electroreduction for Viable Applications

Abstract

CO₂ conversion into value-added chemicals via the electrochemical CO₂ reduction reaction (eCO₂RR) offers substantial environmental and economic benefits. Among all eCO₂RR products, CO shows vital significance due to its extensive application in chemical industrial synthesis, yet its production via eCO₂RR is hindered by the requirements of noble metal catalysts. Zinc-based catalysts are potential cost-effective alternatives while still confronting the inadequacy of eCO₂RR activity and CO selectivity. This study introduces an architecturally optimized zinc hollow-fiber penetration electrode (Zn HPE) that achieves a CO Faradaic efficiency exceeding 90% while sustaining stable operation for 110 h at 800 mA cm^–2. In situ X-ray absorption analysis along with operando Raman spectroscopy confirms the maintenance of metallic Zn⁰ during eCO₂RR. Transmission Fourier transform infrared spectroscopy confirmed that the superior performance of Zn HPE is attributed to its unique penetration effect, ensuring the local enrichment and rapid replenishment of CO₂ at the surface active sites. Besides, the effect of local CO₂ enrichment with high coverage on lowering the energy barrier for forming the *COOH intermediate and subsequent CO₂-to-CO conversion enhancement was also elucidated via density functional theory calculations. The techno-economic analysis further suggests the prominent cost advantage of Zn HPE. This work presents a promising approach for designing efficient CO₂ electroreduction electrodes for viable applications.