Surface Modification of Nano‐Cu₂O for Controlling CO₂ Electrochemical Reduction to Ethylene and Syngas

Abstract

In the surroundings of carbon neutrality, nano-Cu 2 O is considered a promising catalyst for the electrochemical CO 2 reduction reaction (ECO 2 RR), whose improvements in product selectivity still require considerable efforts. Here, we present an efficient strategy for controlling the ECO 2 RR product by modifying the surface of nano-Cu 2 O, i.e., by controlling the exposed facets via a reductantcontrolled method to achieve the highest C 2 H 4 selectivity (Faradic efficiency = 74.1 %) for Cu 2 O-based catalysts in neutral electrolytes, and introducing a well-suited metalorganic framework (MOF) coating on the surface of nano-Cu 2 O to obtain syngas completely with an appropriate H 2 :CO ratio. Detailed mechanism and key intermediate have been illustrated by DFT calculations. Our systematic strategy is expected to control the ECO 2 RR product, improve the selectivity, and provide a reliable method for CO 2 management and the green production of important carbon resources.

Protocol to modify the surface of nano-Cu2O using facet controlling and MOF shell coating

“…In the past research, Cu 2 O nanomaterials with low index facets such as {100}, {110} and {111}, have been well-studied, both in synthesis and applications ( Huang et al., 2012 ; Aran-Ais et al., 2020 ; Hua et al., 2014 ). Further, systematical synthesis of nano-Cu 2 O from low index facets to high index facets, and universal surface coating approach with stable metal organic framework material were proposed in our previous work ( Luo et al., 2022 ).…”

“…Before synthesis, the following preparations should be made.

Scheme 1 Synthetic procedure for Nano-Cu 2 O and Cu 2 O@ZIF-8 Reproduced with permission ( Luo et al., 2022 ).

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“…Second, we describe steps for facet-directed precipitation in which the morphology-dependent ZIF-8 (a type of zeolitic imidazolate frameworks) shells on different nano-Cu 2 O are well introduced. For complete details on the use and execution of this protocol, please refer to Luo et al. (2022) .…”

Operando Constructing Cu/Cu2O Electrocatalysts for Efficient CO2 Electroreduction to Ethanol: CO2-Assisted Structural Evolution of Octahedral Cu2O by Operando CV Activation

“…Apparently, a suitable activation for Cu-based catalysts can induce their evolution toward highly active structures rather than deactivation during surface reconstruction. Combining with the anode reduction and cathode oxidation process, operando cyclic voltammetry (CV) is a powerful technology for electrochemical pretreatment of Cu-based catalysts to enhance generation of C 2 products. ,, Unfortunately, since the CV process involves multiple electrochemical reduction and oxidation kinetic processes, its activation mechanism remains unclear, restricting the establishment of the CV-targeted regulation strategy. Hence, revealing the inert mechanism CV operando pretreatment of the Cu-based catalyst before reaction and forming rich Cu–Cu 2 O grain boundaries are of great significance for enhancing eCO 2 RR to C 2 products.…”

“…Combining with the anode reduction and cathode oxidation process, operando cyclic voltammetry (CV) is a powerful technology for electrochemical pretreatment of Cu-based catalysts to enhance generation of C 2 products. 2,24,25 Unfortunately, since the CV process involves multiple electrochemical reduction and oxidation kinetic processes, its activation mechanism remains unclear, restricting the establishment of the CV-targeted regulation strategy. Hence, revealing the inert mechanism CV operando pretreatment of the Cu-based catalyst before reaction and forming rich Cu−Cu O, the large-scale particle agglomeration was effectively inhibited and the Faraday efficiency of C 2 products (especially ethanol) was improved on Cu/Cu 2 O−CV.…”