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The electrochemical CO2 reduction reaction (CO2RR) to generate chemical fuels such as formate presents a promising route to a carbon‐neutral future. However, its practical application is hindered by the competing CO production and hydrogen evolution reaction (HER), as well as the lack of pH‐universal catalysts. Here, Te‐modified Bi nanorods (Te−Bi NRs) were synthesized through in situ reconstruction of Bi2Te4O11 NRs under the CO2RR condition. Our study illustrates that the complex reconstruction process of Bi2Te4O11 NRs during CO2RR could be decoupled into three distinct steps, i.e. the destruction of Bi2Te4O11, the formation of Te/Bi phases, and the dissolution of Te. The thus‐obtained Te−Bi NRs exhibit remarkably high performance in CO2RR towards formate production, showing high activity, selectivity, and stability across all pH conditions (acidic, neutral, and alkaline). In a flow cell reactor under neutral, alkaline, or acidic conditions, the catalysts achieved HCOOH Faradaic efficiencies of up to 94.3 %, 96.4 %, and 91.0 %, respectively, at a high current density of 300 mA cm−2. Density functional theory calculations, along with operando spectral measurements, reveal that Te manipulates the Bi sites to an electron‐deficient state, enhancing the adsorption strength of the *OCHO intermediate, and significantly suppressing the competing HER and CO production. This study highlights the substantial influence of catalyst reconstruction under operational conditions and offers insights into designing highly active and stable electrocatalysts towards CO2RR. [ABSTRACT FROM AUTHOR]

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Electrochemically reducing CO 2 (CO 2 RR) to high-value chemical products is recognized as a promising route to simultaneously reduce the consumption of fossil fuels and carbon emission. The fabrication of syngas with an appropriate H 2 /CO ratio by CO 2 RR has been widely studied, but the dynamic evolution of the catalyst is still ambiguous. Herein, the reconstruction of CuO/SnO 2 nanosheets (NSs) with a heterojunction structure in the CO 2 RR process was reported by an in situ X-ray diffractometer technique. The products of the CO 2 RR on the optimized CuO/SnO 2 NSs are CO and H 2 , achieving a nearly 100% total Faraday efficiency. Moreover, the resulting syngas is maintained at a constant 2:1 ratio of H 2 /CO over a wide potential of -0.8 to -1.2 V versus the reversible hydrogen electrode. Importantly, the detailed characterizations show that Cu 2+ is reduced to Cu during the CO 2 RR process, while the valence state of Sn remains stable. This study presents strong experimental support for the dynamic evolution process of electrocatalysts in other energy conversion fields.

The electrochemical CO 2 reduction reaction (CO 2 RR) to generate chemical fuels such as formate presents a promising route to a carbon-neutral future. However, its practical application is hindered by the competing CO production and hydrogen evolution reaction (HER), as well as the lack of pH-universal catalysts. Here, Te-modified Bi nanorods (Te-Bi NRs) were synthesized through in situ reconstruction of Bi 2 Te 4 O 11 NRs under the CO 2 RR condition. Our study illustrates that the complex reconstruction process of Bi 2 Te 4 O 11 NRs during CO 2 RR could be decoupled into three distinct steps, i.e., the destruction of Bi 2 Te 4 O 11 , the formation of Te/Bi phases, and the dissolution of Te. The thus-obtained Te-Bi NRs exhibit remarkably high performance in CO 2 RR towards formate production, showing high activity, selectivity, and stability across all pH conditions (acidic, neutral, and alkaline). In a flow cell reactor under neutral, alkaline, or acidic conditions, the catalysts achieved HCOOH Faradaic efficiencies of up to 94.3 %, 96.4 %, and 91.0 %, respectively, at a high current density of 300 mA cm -2 . Density functional theory calculations, along with operando spectral measurements, reveal that Te manipulates the Bi sites to an electron-deficient state, enhancing the adsorption strength of the *OCHO intermediate, and significantly suppressing the competing HER and CO production. This study highlights the substantial influence of catalyst reconstruction under operational conditions and offers insights into designing highly active and stable electrocatalysts towards CO 2 RR., (© 2024 Wiley-VCH GmbH.)

Electrochemically converting carbon dioxide (CO 2 ) into valuable fuels and renewable chemical feedstocks is considered a highly promising approach to achieve carbon neutrality. In this work, a robust interfacial built-in electric field (BEF) has been successfully designed and created in Bi/Bi 2 Te 3 nanowires (NWs). The Bi/Bi 2 Te 3 NWs consistently maintain over 90% Faradaic efficiency (FE) within a wide potential range (-0.8 to -1.2 V), with HCOOH selectivity reaching 97.2% at -1.0 V. Moreover, the FE HCOOH of Bi/Bi 2 Te 3 NWs can still reach 94.3% at a current density of 100 mA cm -2 when it is used as a cathode electrocatalyst in a flow-cell system. Detailed in situ experiments confirm that the presence of interfacial BEF between Bi and Bi/Bi 2 Te 3 promotes the formation of *OHCO intermediates, thus facilitating the production of HCOOH species. DFT calculations show that Bi/Bi 2 Te 3 NWs increase the formation energies of H* and *COOH while reducing the energy barrier for *OCHO formation, thus achieving a bidirectional optimization of intermediate adsorption. This work provides a feasible scheme for exploring electrocatalytic reaction intermediates by using the BEF strategy.