Single atom and defect engineering of CuO for efficient electrochemical reduction of CO₂ to C₂H₄

Abstract

Electrochemical CO2 transformation to high‐value ethylene (C2H4) at high currents and efficiencies is desired and yet remains a grand challenge. We show for the first time that coupling single Sb atoms and oxygen vacancies of CuO enable synergistic electrocatalytic reduction of CO2 to C2H4 at low overpotentials. Highly dispersed Sb atoms occupying metal substitutional sites of CuO are synthesized under mild conditions. The overall CO2 reduction faradaic efficiency (FE) reaches 89.3 ± 1.1% with an FE toward C2H4 exceeding 58.4% at a high‐current density of 500 mA/cm2. Addition of the p‐block metal is found to induce transformation of CuO from flakes to nanoribbons rich in nanoholes and oxygen vacancies, greatly enhancing CO2 adsorption and activation while suppressing hydrogen evolution. Further density functional theory calculations with in situ X‐ray diffraction reveal that combining Sb sites and oxygen vacancies prominently lessen the dimerization energy of adsorbed CO intermediate, thus boosting the conversion of CO2 to produce C2H4. This study provides a new perspective for promoting selective C–C coupling for electrochemical CO2 reduction.

Mechanism insights on single-atom catalysts for CO2conversion

“…16). 116 In summary, three mechanism schemes have been proposed for CO 2 electroreduction to C 2 H 4 : (1) reactions between *COOH and *OCH 2 ; (2) *CO dimerization; (3) C-C coupling between *CO and other intermediates such as *CHO and *OCH 2 . To improve the selectivity towards C 2 H 4 , it is suggested to adjust the distances between two Cu sites and add a second metal.…”

Electrochemical CO2 Reduction by Chalcogenide-Derived Cu Electrocatalysts: A Review

“…The initial branched copper oxide could provide highly active domains between interfaces and junctions, which caused large surface with high local pH for C 2 H 4 production. Chu et al [50] prepared an electrocatalyst coupling single Sb atoms and oxygen vacancies of CuO to enable synergistic electrocatalytic reduction CO [51] . Copyright 2022 Nature.…”

Atomically Dispersed Mn for Electrochemical CO2 Reduction with Tunable Performance

“…[17] As well as SACs maximizing atom utilization efficiency, and the quantum size effect, unsaturated coordination state, and peculiar interaction between metal atoms and the support all contribute to extremely high activity and selectivity. [18][19][20][21][22][23][24][25] In addition, SACs characterized with homogenous catalytic active centers offer a simple model for mechanistic investigations. From this context, a range of emerging SACs, including sp posttransition metals and late transition metals, have been employed in the field of ECR.…”

“…The performance of supported catalysts tends to increase with decreasing metal particle size and size distribution [17] . As well as SACs maximizing atom utilization efficiency, and the quantum size effect, unsaturated coordination state, and peculiar interaction between metal atoms and the support all contribute to extremely high activity and selectivity [18–25] . In addition, SACs characterized with homogenous catalytic active centers offer a simple model for mechanistic investigations.…”