Multi-perspective analysis of CO poisoning in high-temperature proton exchange membrane fuel cell stack via numerical investigation

To comprehensively understand the CO poisoning effect on high-temperature PEMFC stack (HT-PEMFCs), a 3-D numerical HT-PEMFCs model is developed. The crucial anodic kinetic parameters are obtained from experimental data to improve the accuracy of the model. Then, multi-perspective analysis is conducted on different HT-PEMFC stacks with 1, 3, and 5 cells working at 160 °C with 3 mol% CO in H₂. Besides, parametric simulations are conducted on the three-cell stack. It is found that the CO and H₂ coverage varies between cells in the stack due to the temperature distribution difference, and the stack with more cells as well as the middle-cell of multi-cell stack have better performance, higher H₂ coverage, lower CO coverage due to higher internal temperature. However, too high local temperature not only reduce the CO coverage but reduce the H₂ coverage and increase the anode overpotential. The resistance to CO poisoning can be improved by increasing operating temperature, but when CO₂ and water vapor are introduced into the anode, the H₂ coverage decreases and the CO coverage increases due to the decrease of H₂ concentration. The study clearly demonstrated that high performance and high CO resistance can be achieved by carefully regulating the operating conditions.