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Metal-free catalytic conversion of CO2 is expected to achieve carbon neutrality. However, non-metallic catalytic sites for highly selective and efficient conversion of CO2 to ethanol are challenging. Here, a metal-free catalyst (B4@g-C3N4) has been reported for the first time for the efficient reduction of CO to ethanol. Utilizing electron "accept-donation" analysis, we show that the binding of tri-coordinated B atoms to CO is very mild compared to metal sites and bi-coordinated B atoms. The B4@g-C3N4 catalyst effectively reduced the free energy barrier for direct dimerization of CO to 0.18 eV. The limiting voltage in the entire reduction of CO to CH3HC2OH is −0.19 V, which is better than that of other catalysts, including four-atom metal clusters Cu4–C5N2H2 (−0.50 V) and Cu2Zn2–C5N2H2 (−0.46 V) just proposed (J. Am. Chem. Soc. 2023, 145, 7030–7039). The metal-free electrocatalyst has an absolute selectivity advantage since the molar ratio of the C2 product CH3CH2OH to the C1 product CH4 is 2.55 × 105 : 1. Moreover, due to its extremely high stability, the catalyst designed in this paper holds great promise for synthesis. The above analysis shows that the B4@g-C3N4 catalyst constructed under the new concept proposed by us can achieve the goal of electrocatalytic CO reduction to ethanol. Our work reports the first metal-free electrocatalyst to date for the reduction of CO to ethanol, providing a theoretical basis for promoting the achievement of sustainable carbon neutrality goals. [ABSTRACT FROM AUTHOR]

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A promising pathway for carbon usage and energy storage is electrocatalytic reduction of CO to form high-value multi-carbon products. Herein, the d–p coupled triatomic catalyst CuB2@g-C3N4 with significant activity and selectivity for ethanol is presented for the first time. Density functional theory calculations elucidate that these spatially confined triatomic centers are capable of immobilizing multiple CO molecules, providing an exclusive reaction channel for direct C–C coupling. The CuB2@g-C3N4 catalyst can effectively reduce the energy barrier of CO dimerization to 0.46 eV. The limiting potential is only −0.19 V, which is much smaller than that of other Cu-based catalysts. Additionally, the CuB2@g-C3N4 catalyst can effectively inhibit the generation of competing C1 products and hydrogen evolution reactions. Excitingly, CuB2 loading makes g-C3N4 more optically active in visible and even infrared light. This work provides important ideas for the atomically precise design of novel d–p coupled catalysts for the direct conversion of CO2/CO into energetic fuels and high-value chemicals. [ABSTRACT FROM AUTHOR]

Integration of non-noble transition metal oxides with graphene is known to construct high-activity electrocatalysts for oxygen evolution reduction (OER). In order to avoid the complexity of traditional synthesis process, a facile electrochemical method is elaborately designed to engineer efficient WO3-x/graphene (photo-)electrocatalyst for OER by a two-electrode electrolysis system, where graphite cathode is exfoliated into graphene and tungsten wire anode evolves into VO-rich WO3-x profiting from formed reductive electrolyte solution. Among as-prepared samples, WO3-x/G-2 shows the best electrocatalytic performance for OER with an overpotential of 320 mV (without iR compensation) at 10 mA/cm2, superior to commercial RuO2 (341 mV). With introduction of light illumination, the activity of WO3-x/G-2 is greatly enhanced and its overpotential decreases to 290 mV, benefiting from additional reaction path produced by photocurrent effect and extra active sites generated by photogenerated carriers (h+). Characterization results indicate that both VO-rich WO3-x and graphene contribute to the efficient OER performance. The activity of WO3-x for OER is decided by the synergistic effect between VO concentration and particle size. The graphene could not only disperse WO3-x nanoparticles, but also improve the holistic conductivity and promote electron transmission. This work supports a novel method for engineering WO3-x/graphene composite for highly efficient (photo-)electrocatalytic performance for OER. [ABSTRACT FROM AUTHOR]