Highly Efficient CO2 Reduction at Steady 2 A cm-2 by Surface Reconstruction of Silver Penetration Electrode

Electroreduction of CO2 to CO is a promising route for greenhouse gas resource utilization, but it still suffers from impractical current density and poor durability. Here, a nanosheet shell (NS) vertically standing on the Ag hollow fiber (NS@Ag HF) surface formed by electrochemical surface reconstruction is reported. As-prepared NS@Ag HF as a gas penetration electrode exhibited a high CO faradaic efficiency of 97% at an ultra-high current density of 2.0 A cm-2 with a sustained performance for continuous >200 h operation. The experimental and theoretical studies reveal that promoted surface electronic structures of NS@Ag HF by the nanosheets not only suppress the competitive hydrogen evolution reaction but also facilitate the CO2 reduction kinetics. This work provides a feasible strategy for fabricating robust catalysts for highly efficient and stable CO2 reduction.

Hierarchical micro/nanostructured silver hollow fiber boosts electroreduction of carbon dioxide

Efficient conversion of CO₂ to commodity chemicals by sustainable way is of great significance for achieving carbon neutrality. Although considerable progress has been made in CO₂ utilization, highly efficient CO₂ conversion with high space velocity under mild conditions remains a challenge. Here, we report a hierarchical micro/nanostructured silver hollow fiber electrode that reduces CO₂ to CO with a faradaic efficiency of 93% and a current density of 1.26 A · cm⁻² at a potential of −0.83 V vs. RHE. Exceeding 50% conversions of as high as 31,000 mL · g_cat⁻¹ · h⁻¹ CO₂ are achieved at ambient temperature and pressure. Electrochemical results and time-resolved operando Raman spectra demonstrate that enhanced three-phase interface reactions and oriented mass transfers synergistically boost CO production.

An activated silver hollow fiber electrode enables enhanced triphasic interface reactions and oriented mass transfers synergistically, facilitating efficient CO₂ conversion (> 50%) to boost CO production with a current density of 1.26 A · cm⁻².