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

Abstract

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.

Recent advances in dynamic reconstruction of electrocatalysts for carbon dioxide reduction

“… 78 Vertical standing Ag nanosheet shells were grown on the outer surface of Ag hollow fiber by an electrochemical surface reconstruction approach, which achieved a high FE of CO 2 to CO over 97% at a current density of 2.0 A cm −2 . 79

Figure 4 Reconstruction of other metal-based catalysts (A) Schematic depiction of the morphological evolution of Pd/PdH x catalysts. Reproduced with permission.

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“…The ex situ XRD and operando Raman results clearly demonstrated these phase transition processes between AgCl and Ag compositions during in situ reconstruction of the Ag HF catalyst. 165 The surface morphology and chemical state of the SnO x /AgO x catalyst at different reduction conditions were monitored by quasi- in situ XPS and operando X-ray absorption near-edge structure spectroscopy (XANES). The stable Sn δ+ /Sn species formed on the SnO x /AgO x surface acted as a key site for CO 2 RR, resulting in high selectivity and long-term CO 2 -to-CO and formate conversion with a total FE of 95%.…”

Sulfidation-Induced Surface Local Electronic and Atomic Structures in a Silver Catalyst Enables Silicon Photocathode for Selective and Efficient Photoelectrochemical CO2 Reduction

“…Nonetheless, bulk Ag catalysts exhibit limited activity and selectivity for CO formation. Extensive efforts have thus been undertaken to further improve their CO 2 RR performance by modulating surface atomic arrangements and electronic structures. − For example, Luo et al proved that triangular Ag nanoplates exhibit considerably superior selectivity and activity toward CO formation in comparison with bulk Ag and the similarly sized Ag nanoparticles, attributed to the predominant Ag(100) facet and the appropriate edge-to-corner ratio . Combining experimental investigation with theoretical analysis, Bell et al proposed the facet-dependent activity of Ag on CO evolution, where the Ag(110) thin film revealed higher intrinsic CO 2 RR activity to the Ag(100) and Ag(111) thin films .…”

Breaking the scaling relationship via lattice expansion of Ag for CO2 electroreduction over a wide potential window

“…34,35 Furthermore, the adsorption of halogen ions on the Ag surface has been proved to improve CO 2 RR performance by attracting CO 2 molecular. [36][37][38][39][40] Despite the remarkable achievements in CO 2 RR performance toward CO using developed Ag-based electrocatalysts, the potential window to maintain the high CO 2 RR performance is still too narrow. This makes them unappealing in practical applications because of voltage fluctuation in unstable renewable energy sources.…”