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

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.