Scaling CO Electrolyzers for Carbon-Neutral Chemical Synthesis

The industrial-scale implementation of carbon monoxide (CO) electrolysis provides a sustainable route to renewable fuels and chemicals. However, scaling up the process faces the challenge of maintaining high Faradaic efficiencies (FEs) and current densities. Here, we address this issue by reinforcing the gas diffusion layer (GDL), optimizing the CO flow rate, and improving heat management. These allow us to fill the performance gap between different electrolyzer stacks from 5 cm² to 3×50 cm². Across this scale range, we report FEs of ~80 % for multicarbon (C₂₊) products at 500 mA cm⁻², and the peak power reaches 580 W, 80 times that of the 5 cm² electrolyzer. This work provides practical guides for developing CO electrolysis from bench science to industrial chemical production technology.