Paired Electrolysis by Regulated Electronic Distribution and Lowering of Overpotential with Enhanced Current Density

Abstract

Paired electrolysis is a process that always involves two half-electrode reactions: anodic oxidation and cathodic reduction. The cathodic process, which includes reactions such as hydrogen evolution (HER) or CO2 electroreduction (eCO2R), enables selective oxidation and facilitates an electrified simultaneous reaction with maximized atomic and energy efficiency. The optimized adsorption of intermediates associated with selective two-electron reaction pathways can enhance the selectivity and activity of the simultaneous electrodes. This review demonstrates the potential for atomic configurations and electronic properties to be fine-tuned to improve electrode activity and intrinsic electronics, thereby optimizing single-product formation. We explore using single-atom electrode materials, nanoarray wires, and self-supported electrodes to achieve a synergistic effect in paired electrolysis. The arrangement of atomic structures in the electrodes aids in converting energy through electrochemical energy storage and conversion driven by paired electrolysis. The article emphasizes the importance of uncovering critical intermediates that lead to H2 production through detailed analysis using in situ spectroscopies, such as Raman and X-ray absorption spectroscopy. We showcase the electronic properties of the electrodes, demonstrating long-term stability in a biomass-derived anodic oxidation two-electrode system. This system exhibits performance several times greater than existing HER/OER two-electrode systems, while requiring significantly less energy. Thus, this article presents a new paradigm for advanced paired-electrolysis systems, promoting concurrent activity at simultaneous electrodes to accelerate electroreformation, opening up new avenues for multiple processes, including H2 production, eCO2R, and biomass upgrading.