Electrochemical CO2 reduction coupled with alternative oxidation reactions: Electrocatalysts, electrolytes, and electrolyzers

Electrocatalytic carbon dioxide reduction (CO2RR) is a promising strategy to achieve carbon neutrality. Nevertheless, its practical viability is hindered by the energy-consuming anodic oxygen evolution (OER) process. In recent years, researchers have attempted to break this limitation by some novel anodic OER substitution reactions to improve the overall economic profitability. This article aims to provide a comprehensive review covering the recent development of integrated CO2RR systems with alternative OER oxidation reactions. Starting from the presentation of fundamental considerations of electrolytic configurations, energy efficiency, value-added products and tech-economic analysis for high-performance integrations, the recent innovative anodic reactions are then summarized and thoroughly analyzed including the reactions involving alcohols, biomass, chlorine, water contaminants oxidations and chemicals electrosynthesis, with the focus on electrocatalysts design, electrolyte selection and system configurations. Finally, the current challenges and future perspectives are discussed to achieve the dual goals of sustainability and profitability in an economical and energy-efficient way.