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The efficient conversion of CO2 to value‐added products represents one of the most attractive solutions to mitigate climate change and tackle the associated environmental issues. In particular, electrochemical CO2 reduction to fuels and chemicals has garnered tremendous interest over the last decades. Among all products from CO2 reduction, formic acid is considered one of the most economically vital CO2 reduction products. P‐block metals (especially Bi, Sn, In, and Pb) have been extensively investigated and recognized as the most efficient catalytic materials for the CO2 electroreduction to formate. Despite remarkable progress, the future implementation of this technology at the industrial‐scale hinges on the ability to solve remaining roadblocks. In this review, the current research status, challenges, and prospects of p‐block metal‐based catalysts primarily for CO2 electroreduction to formate are comprehensively reviewed. The rational design and nanostructure engineering of these p‐block metal catalysts for the optimization of their electrochemical performances are discussed in detail. Subsequently, the recent progress in the development of state‐of‐the‐art operando characterization techniques together with the design of advanced electrochemical cells to uncover the intrinsic catalysis mechanism is discussed. Lastly, a perspective on future directions including tackling critical challenges to realize its early industrial implementation is presented. [ABSTRACT FROM AUTHOR]

The efficient conversion of CO2 to value‐added products represents one of the most attractive solutions to mitigate climate change and tackle the associated environmental issues. In particular, electrochemical CO2 reduction to fuels and chemicals has garnered tremendous interest over the last decades. Among all products from CO2 reduction, formic acid is considered one of the most economically vital CO2 reduction products. P‐block metals (especially Bi, Sn, In, and Pb) have been extensively investigated and recognized as the most efficient catalytic materials for the CO2 electroreduction to formate. Despite remarkable progress, the future implementation of this technology at the industrial‐scale hinges on the ability to solve remaining roadblocks. In this review, the current research status, challenges, and prospects of p‐block metal‐based catalysts primarily for CO2 electroreduction to formate are comprehensively reviewed. The rational design and nanostructure engineering of these p‐block metal catalysts for the optimization of their electrochemical performances are discussed in detail. Subsequently, the recent progress in the development of state‐of‐the‐art operando characterization techniques together with the design of advanced electrochemical cells to uncover the intrinsic catalysis mechanism is discussed. Lastly, a perspective on future directions including tackling critical challenges to realize its early industrial implementation is presented. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of carbon dioxide (CO2) to ethanol is a promising strategy for global warming mitigation and resource utilization. However, due to the intricacy of C─C coupling and multiple proton–electron transfers, CO2‐to‐ethanol conversion remains a great challenge with low activity and selectivity. Herein, it is reported a P‐doped graphene aerogel as a self‐supporting electrocatalyst for CO2 reduction to ethanol. High ethanol Faradaic efficiency (FE) of 48.7% and long stability of 70 h are achieved at −0.8 VRHE. Meanwhile, an outstanding ethanol yield of 14.62 µmol h−1 cm−2 can be obtained, outperforming most reported electrocatalysts. In situ Raman spectra indicate the important role of adsorbed *CO intermediates in CO2‐to‐ethanol conversion. Furthermore, the possible active sites and optimal pathway for ethanol formation are revealed by density functional theory calculations. The graphene zigzag edges with P doping enhance the adsorption of *CO intermediate and increase the coverage of *CO on the catalyst surface, which facilitates the *CO dimerization and boosts the EtOH formation. In addition, the hierarchical pore structure of P‐doped graphene aerogels exposes abundant active sites and facilitates mass/charge transfer. This work provides inventive insight into designing metal‐free catalysts for liquid products from CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Facilely tailored electrocatalyst with high-efficiency and durability for carbon dioxide (CO2) to carbon monoxide (CO) conversion is appealing but remains challenging. Herein, small nickel nanoparticles (about 19.4 nm) confined in nitrogen-doped carbon (Ni NPs@N–C) with narrow size distribution are successfully constructed via a facile one-step calcination strategy of Ni containing MOF compounds. By virtue of the protective N-doped graphitized carbon shell and the uniformly distributed fine Ni nanoparticles in a narrow range from 13 to 21 nm, the as-obtained Ni NPs@N–C can exclusively convert CO2 into CO with excellent Faradaic efficiency (FE) of 96.8% at − 1.0 V (vs. RHE), as well as the superior long-term catalytic stability over 24 h. Moreover, a high current density of more than 200 mA cm−2 with a stable CO FE of 92% can be achieved in a flow cell configuration. This work paves a new way for the facile and potentially scale preparation of small metal nanoparticles for efficient CO2- to-CO conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of f-Cu 2 O catalyst enclosed with rich oxygen vacancy defects. • The f-Cu 2 O catalyst can electrochemical reduction CO 2 to ethanol and formate. • The peak Faradaic efficiency for liquid products was up to 95.5%. • The Faradaic efficiency of ethanol can reach 52.6% in a H-cell. • In-situ Raman spectra and DFT calculation reveal the reaction mechanism. The electrochemical reduction of CO 2 presents a promising pathway for storing intermittent renewable energy in the form of chemical bonds, thereby mitigating CO 2 emissions and enabling the production of sustainable fuels. In this work, we demonstrate nanoscale engineering of oxygen vacancy and morphology simultaneously on Cu 2 O catalysts for electrochemical reduction of CO 2 to liquid products (formate and ethanol). By comparing the performance of cube- and tetrakaidecahedron-like Cu 2 O catalysts, we have demonstrated that the flower-like Cu 2 O catalyst, enclosed with rich oxygen vacancy defects, exhibited superior performance in the reduction of CO 2 to liquid products. Moreover, the synergetic role of Cu+ also contributed to the enhanced activity by promoting CO 2 adsorption and facilitating C–C coupling. As a result, the peak Faradaic efficiency (FE) for liquid products of 95.5 % was obtained, associated with a high ethanol FE of 52.6 % and formation rate of 23.8 μmol h−1 cm−2 within a H-cell. Furthermore, within a flow cell configuration, we have observed a significant improvement in the generation of formate, maintaining FE values above 70 % even under high current densities of up to 400 mA cm−2. In-situ Raman spectroscopic measurements allow us to identify and track key intermediates involved in the CO 2 reduction to formate and ethanol. This detailed understanding of the reaction pathways adds to our fundamental knowledge and provides valuable insights for the development of morphology-controlled electrocatalysts targeting efficient conversion of CO 2 into liquid products. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic properties are modulated to enhance the CO 2 RR activity by triple-heteroatoms doping. • Reaction intermediates are directly detected and analyzed by in-situ Raman spectra. • High CO FE is achieved at a low onset overpotential of 270 mV. • A high current density of 245 mA cm−2 and stable FE CO above 98% are simultaneously achieved in a flow-cell. Electroreduction of CO 2 to value-added chemicals using metal-free carbon catalysts is attractive, but single N-doped carbons suffer from poor efficiency (<90%) and low current density (<2 mA cm−2). Herein, we report a facile and scalable preparation of ternary heteroatoms (N, S, P)-doped carbon electrocatalyst to enhance electrochemical activity, because the multi-heteroatoms with different sizes and electronegativities can modulate the electronic properties to facilitate CO 2 localization and provide abundant active sites with enhanced charge-carrier concentrations. It exhibits high activity toward CO 2 electroreduction to CO activity with 92% CO Faradaic efficiency (FE CO) at −0.7 V RHE and low onset overpotential of 270 mV. The promising potential of industrial application is manifested by the high current density of 245 mA cm−2 and stable FE CO above 98% in a flow-cell configuration. Moreover, in-situ Raman spectroscopy demonstrates that *COOH is the key intermediate in CO 2 -to-CO conversion. Density functional theory calculations reveal that the synergistic effect of N, S, and P heteroatoms boosts the catalytic activity by greatly decreasing the free energy barrier of *COOH formation. Furthermore, the morphological benefit of hierarchically porous structures plays a synergistic role in improving the CO 2 reduction activity. [ABSTRACT FROM AUTHOR]