The application of renewable electricity to convert carbon dioxide molecules into high value-added chemicals is one of the key measures to deal with disastrous environmental and energy issues. Among the many available electrocatalyst materials, metal copper is the most common electrocatalyst material that can activate stable carbon dioxide molecules due to the suitable adsorption and desorption capabilities between its surface with active intermediates. What is more, the adsorbed intermediate species could undergo some C–C coupling reactions on the Cu surface to generate some high value-added hydrocarbons. However, the low Faraday efficiency, high overpotential, and low limiting current density of the target product in the catalytic process have been the main issues that plagued researchers. Various controlling strategies of the catalyst in the electrocatalytic carbon dioxide reduction reaction (ECDRR) have a great influence on the performance of the catalyst. Their morphology, composition, geometric structure, and electronic structure affect the role of local active sites and adsorption intermediates and ultimately result in different product distributions of electrocatalysts. Through the investigation and collation of related series of literature, this minireview gives examples of four types of Cu-based electrocatalysts commonly used in ECDRR, namely single metal-phase Cu catalyst, Cu-based bimetallic catalysts, oxide-derived Cu (OD-Cu) catalysts, and Cu-doped carbon-based (Cu–C) catalyst. The research progress of these four types of electrocatalysts in recent years is summarized in detail, and the strategies to improve their electrocatalytic activity are discussed to provide a reference for developing high-efficiency Cu-based ECDRR electrocatalysts. Finally, we put forward some challenges and opportunities that Cu-based materials would face in the development of ECDRR technology in the future.

Minireview on the Commonly Applied Copper-Based Electrocatalysts for Electrochemical CO2 Reduction

The electrochemical CO2 reduction reaction (CO2RR) provides a route to store intermittent electricity in the form of fuels like methane. We reasoned that disrupting C-C coupling while maintaining high ∗CO coverage could enhance methane selectivity and suppress the hydrogen evolution reaction (HER). We studied the effect of doping CuAl, a material at the top of the CO2RR activity and selectivity volcano plot, with elements having low ∗CO binding energies: Au, Zn, and Ga. Encouraged by initial improvements in selectivity to methane, we optimized the Ga content and showed that the presence of uniformly dispersed Ga is crucial in CO2RR-to-methane performance enhancement. We rule out porosity and roughness and conclude that the presence of Ga in the doped catalysts enables high methane selectivity. The Ga-doped CuAl catalysts achieve a methane Faradaic efficiency (FE) of 53% by suppressing HER to 23% in neutral electrolyte at −1.4 V versus reversible hydrogen electrode. 

Ga doping disrupts C-C coupling and promotes methane electroproduction on CuAl catalysts

Robust electrocatalysts with high activity and selectivity are critically important for the industrial application of carbon dioxide (CO2) electroreduction. Functional materials with hetero-interfaces have recently emerged as a promising class of electrocatalysts for CO2 reduction. Herein, we review a broad spectrum of recently developed hetero-interface catalysts pertaining to electrocatalytic CO2 reduction and the synthetic strategy of these materials. The hetero-catalysts can be broadly categorized into three groups by the composition of hetero-interfaces: (1) metal-metal hetero-interface, (2) metal-inorganic compound hetero-interface, and (3) metal-organic molecule hetero-interface. The special interfacial effects would have significant impacts on the reaction pathways of CO2 reduction, leading to modulated catalytic activity and product selectivity. Detailed discussions provide a rational understanding of how the hetero-interfaces enhance the catalytic performance. Finally, we discuss the current challenges and possible future directions for advanced hetero-catalysts toward efficient CO2 reduction. 

Recent advances in metal-based electrocatalysts with hetero-interfaces for CO2 reduction reaction

Summary Robust electrocatalysts with high activity and selectivity are critically important for the industrial application of carbon dioxide (CO2) electroreduction. Functional materials with hetero-interfaces have recently emerged as a promising class of electrocatalysts for CO2 reduction. Herein, we review a broad spectrum of recently developed hetero-interface catalysts pertaining to electrocatalytic CO2 reduction and the synthetic strategy of these materials. The hetero-catalysts can be broadly categorized into three groups by the composition of hetero-interfaces: (1) metal-metal hetero-interface, (2) metal-inorganic compound hetero-interface, and (3) metal-organic molecule hetero-interface. The special interfacial effects would have significant impacts on the reaction pathways of CO2 reduction, leading to modulated catalytic activity and product selectivity. Detailed discussions provide a rational understanding of how the hetero-interfaces enhance the catalytic performance. Finally, we discuss the current challenges and possible future directions for advanced hetero-catalysts toward efficient CO2 reduction.

Electrochemical CO2 reduction reaction (CO2RR) has received significant research interest in recent years due to its potential to mitigate carbon emissions while providing valuable fuels and chemicals. The performance of...

Development of catalysts and electrolyzers toward industrial-scale CO2 electroreduction

An oxidized copper species (Cuδ+) on the metallic copper surface is critical to the activity and selectivity of electrochemical reduction of CO2 gas. However, Cuδ+ species are easily reduced under ...

Ruize Wang

Papers

Engineering a Cu/ZnOx Interface for High Methane Selectivity in CO2 Electrochemical Reduction

A Micron-Size Carbon-Free K3V2O2(PO4)2F Cathode with High-Rate Performance for Potassium-Ion Batteries