The Role of Electrocatalysts in the Electrochemical Conversion of CO₂ into Multi-Carbon Products (C₂₊): A Review

In recent years, the electrochemical conversion of CO₂ gasses into renewable fuels (e.g., ethylene, ethanol, and propanol) has attracted much attention. In this process, electrocatalysts play a crucial role in accelerating the CO₂ reduction reaction (CO₂RR) process. In this review, the role of electrocatalysts in the synthesis of C₂₊ products (e.g., ethanol, ethylene, and propanol) from CO₂ was investigated. To this end, various classifications of electrocatalysts such as metals, metal oxides, metal alloys, covalent organic frameworks (COFs), carbon-based electrocatalysts, and metal–organic frameworks (MOFs) and their utilization in CO₂ conversion into C₂₊ chemicals were fully investigated. Also, the impact of various factors such as catalyst stability, temperature, membrane type, pressure, current density, pH, and the type of electrolyte on the CO₂RR process to generate C₂₊ valuable products was investigated. Moreover, the mechanism of this process for producing renewable fuels was investigated. Furthermore, the limitations and future perspective of CO₂RR were surveyed. Finally, the industrial application of this process for producing value-added products was investigated. Based on our investigation, Cu and Cu₂O-based electrocatalysts are suitable catalysts for C₂₊ products, particularly ethylene and ethanol.