Scaling the Electrochemical Conversion of CO<sub>2</sub> to CO
Kai Han, Ben C. Rowley, Maarten P. Schellekens, Sander J. T. Brugman, M. P. de Heer, Lucas Keyzer, Paul J. Corbett
Abstract
The key challenges for the industrial electrolysis of CO 2 into CO are the low CO 2 conversion, restricted scale-up, and poor long-term operation. Systematic process design and electrolyzer engineering are essential for addressing these challenges and exploiting the full potential of commercial CO 2 electrolysis. In this study, we employed a bipolar membrane (BPM) in a pressurized electrolyzer with a 25 cm 2 active area to achieve a maximum FE CO of 93% with a cell voltage of 3.5 V and a maximum CO 2 single-pass conversion of 70% without detecting CO 2 crossover. In addition, we upscaled the system active area from 5 to 250 cm 2 and showed that this increase did not result in a loss of performance. In particular, the performance on the pressurized 100 cm 2 electrolyzer established an average FE CO of 85% with a CO 2 single-pass conversion of 60% for over 120 h. This provides practical approaches for transitioning from laboratory-scale to industrial-scale electrolysis.