@article{35479,
  author = {ChungHyuk Lee and Xiaohua Wang and Jui-Kun Peng and Adlai Katzenberg and Rajesh K Ahluwalia and Ahmet Kusoglu and Siddharth Komini Babu and Jacob S Spendelow and Rangachary Mukundan and Rodney L Borup},
  title = {Toward a Comprehensive Understanding of Cation Effects in Proton Exchange Membrane Fuel Cells},
  abstract = {<p><span>Metal alloy catalysts (e.g., Pt–Co) are widely used in fuel cells for improving the oxygen reduction reaction kinetics. Despite the promise, the leaching of the alloying element contaminates the ionomer/membrane, leading to poor durability. However, the underlying mechanisms by which cation contamination affects fuel cell performance remain poorly understood. Here, we provide a comprehensive understanding of cation contamination effects through the controlled doping of electrodes. We couple electrochemical testing results with membrane conductivity/water uptake measurements and impedance modeling to pinpoint where and how the losses in performance occur. We identify that (1) ∼44% of Co</span><span>2+</span><span>&nbsp;exchange of the ionomer can be tolerated in the electrode, (2) loss in performance is predominantly induced by O</span><span>2</span><span>&nbsp;and proton transport losses, and (3) Co</span><span>2+</span><span>&nbsp;preferentially resides in the electrode under wet operating conditions. Our results provide a first-of-its-kind mechanistic explanation for cation effects and inform strategies for mitigating these undesired effects when using alloy catalysts.</span></p>},
  year = {2022},
  journal = {ACS Applied Materials & Interfaces},
  volume = {14},
  pages = {35555 - 35568},
  month = {08/2022},
  issn = {1944-8244},
  url = {https://pubs.acs.org/doi/10.1021/acsami.2c07085},
  doi = {10.1021/acsami.2c07085},
  language = {eng},
}