Sn Dopants with Synergistic Oxygen Vacancies Boost CO₂ Electroreduction on CuO Nanosheets to CO at Low Overpotential

Abstract

Using the electrochemical CO 2 reduction reaction (CO 2 RR) with Cu-based electrocatalysts to achieve carbonneutral cycles remains a significant challenge because of its low selectivity and poor stability. Modulating the surface electron distribution by defects engineering or doping can effectively improve CO 2 RR performance. Herein, we synthesize the electrocatalyst of V o -CuO(Sn) nanosheets containing oxygen vacancies and Sn dopants for application in CO 2 RR-to-CO. Density functional theory calculations confirm that the incorporation of oxygen vacancies and Sn atoms substantially reduces the energy barrier for *COOH and *CO intermediate formation, which results in the high efficiency, low overpotential, and superior stability of the CO 2 RR to CO conversion. This electrocatalyst possesses a high Faraday efficiency (FE) of 99.9% for CO at a low overpotential of 420 mV and a partial current density of up to 35.22 mA cm −2 at −1.03 V versus reversible hydrogen electrode (RHE). The FE CO of V o -CuO(Sn) could retain over 95% within a wide potential area from −0.48 to −0.93 V versus RHE. Moreover, we obtain long-term stability for more than 180 h with only a slight decay in its activity. Therefore, this work provides an effective route for designing environmentally friendly electrocatalysts to improve the selectivity and stability of the CO 2 RR to CO conversion.

Electroreduction of CO2 to syngas with controllable H2/CO ratios in a wide potential range over Ni–N co-doped ultrathin carbon nanosheets

“…S8 †), further proving that the Ni-N x active sites can accelerate the reaction kinetics of Ni/N-C catalysts in the CO 2 RR. 49,50 In addition, Fig. S9 Thus, the higher intrinsic activity of Ni/N-C-900 is attributed to its unique Ni-N x sites.…”

“…S8†), further proving that the Ni–N x active sites can accelerate the reaction kinetics of Ni/N–C catalysts in the CO 2 RR. 49,50…”

Bionic Construction of Helical Bi2O3 Microfibers for Highly Efficient CO2 Electroreduction

“…As shown in Figure 2d, the EPR intensity of all the HBMs was enhanced compared with Bi 2 O 3 powders, especially for HBM‐600. Thus, we speculated that the lattice strain derived from the cotton template favored the formation of oxygen vacancies of Bi 2 O 3 during the pyrolysis of Bi‐Cotton [29,30] …”

“…Thus, we speculated that the lattice strain derived from the cotton template favored the formation of oxygen vacancies of Bi 2 O 3 during the pyrolysis of Bi-Cotton. [29,30] To investigate the catalytic performance of HBMs, we firstly evaluated the eCO 2 R performance on different materials as made in an H-cell. Before the electrochemical tests, high-purity CO 2 gas was firstly passed into 0.1 m KHCO 3 electrolyte at a constant flow rate of 20 sccm for at least 30 min until saturation.…”

Enhancing Selective Electrochemical CO2 Reduction by In Situ Constructing Tensile-Strained Cu Catalysts

“…Han and co-workers have developed Sn-doped CuO electrocatalysts for robust CO 2 reduction to CO due to the stabilization of Cu &+ . Through surface engineering, Sn-doped CuO nanosheets with oxygen vacancies were demonstrated to show high activity and selectivity toward CO . In contrast, Sun and co-workers reported that the combination of Sn doping and oxygen vacancies can synergistically boost CO 2 reduction to C 2 H 4 over Sn-doped CuO nanosheets .…”