Effect of Dual-Flow Channel Structures on Electrochemical CO₂ Reduction in Proton Exchange Membrane Electrolyzers

Greenhouse gases such as carbon dioxide and methane are responsible for intensifying global warming. Consequently, a reduction in power plant outputs and an increase in capture and storage on-site are required to reduce greenhouse gas emissions. Recently, research has focused on an electrochemical CO₂ reduction method because the amount of CO₂ reduction can be controlled by adjusting the operating voltage. However, to scale up the electrochemical system while maintaining a high conversion rate in a large cell, a suitable flow field of the cell must be optimized. The transparent cell structure presented in this study allows visualization of the distribution of the two-phase flow. Accordingly, dual-flow channels consisting of main and sub-channels have been designed. Furthermore, multiple configurations of the dual-flow channels and locations of the catalyst layer have been compared. The interdigitated sub-channels and inverted layered cell structures can supply gas and liquid to the catalyst layer via distinct pathways, allowing for uniform flow distribution to each channel.