Key points are not available for this paper at this time.
The electrochemical CO2 reduction reaction (CO2RR) in a zero-gap electrolyzer is a promising pathway for carbon fixation via utilizing intermittent renewable energies to produce synthetic fuels and feedstocks, contributing to climate change mitigation. As a critical component of the electrolyzer, the flow field affects its performance by influencing the CO2 transport. A 3D numerical model of the electrolyzer is critical for flow field optimization. However, numerical studies on the flow field in zero-gap electrolyzers are currently lacking. This study established a 3D model for CO2 electrolyzers and validated it by experiments under acidic conditions. Based on this model, we investigated the effects of flow field designs on the performance of zero-gap electrolyzers. Two typical flow fields used in zero-gap CO2 electrolyzers, including serpentine and parallel flow field designs, were evaluated, with the serpentine flow field demonstrating better CO2 transport characteristics and performance. Then, the serpentine flow field was designed by further optimizing the channel-to-rib ratio and the channel depth within the flow field. The results indicate that a larger channel-to-rib ratio and shallower flow channels facilitate an increased average CO2 flux and average CO2 concentration within the catalyst layer. This research provides insights into flow field designs for zero-gap electrolyzers.
Wang et al. (Mon,) studied this question.