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

Abstract

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.