@article{33311,
  author = {Haoran Yu and Nemanja Danilovic and Yang Wang and William Willis and Abhinav Poozhikunnath and Leonard Bonville and Chris Capuano and Katherine Ayers and Radenka Maric},
  title = {Nano-size IrOx catalyst of high activity and stability in PEM water electrolyzer with ultra-low iridium loading},
  abstract = {<div id="abs0015" class="abstract author"><div id="abst0015"><p id="spar0110">The balance of catalyst loading, activity and stability remains a challenge for the anode of proton exchange membrane (PEM) water electrolyzers. Here we report a nano-size IrOx/Nafion<span>{\textregistered}</span>\&nbsp;composite catalyst that exhibits both outstanding activity for oxygen evolution reaction (OER) and stability in a PEM water electrolyzer. The IrOx/Nafion<span>{\textregistered}</span>\&nbsp;catalyst layer is fabricated using a flame-based cost-effect process, reactive spray deposition technology. The IrOx/Nafion<span>{\textregistered}</span>\&nbsp;catalyst shows \&gt;10 times improvement in OER mass activity compared to IrOx nanoparticles synthesized using the wet chemistry method. The IrOx/Nafion<span>{\textregistered}</span>\&nbsp;catalyst also achieved \~{}4,500\&thinsp;h of stable operation in MEA electrolyzer at 1.8\&thinsp;A cm<span>-2</span>\&nbsp;and 80\&thinsp;{\textdegree}C with ultra-low iridium loading of 0.08\&thinsp;mg\&thinsp;cm<span>-2</span>. Analysis of the IrOx structure and the electrochemical performance revealed three key factors for balancing high stability and activity: (1) high ratio of Ir (IV) to Ir (III) species and high content of hydroxide on the surface; (2) high anodic charge and surface area due to nano-size IrOx particles that are well-dispersed in the Nafion<span>{\textregistered}</span>\&nbsp;ionomer electrolyte; (3) homogeneous anode catalyst layer morphology.</p></div></div>},
  year = {2018},
  booktitle = {Applied Catalysis B: Environmental},
  journal = {Applied Catalysis B: Environmental},
  series = {Applied Catalysis B: Environmental},
  volume = {239},
  pages = {133 - 146},
  month = {12/2018},
  issn = {09263373},
  doi = {10.1016/j.apcatb.2018.07.064},
  language = {eng},
}