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

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.