Optimizing the Atomic Structure of Ruthenium Deposited on Pt/C Cathode Catalysts to Enhance Durability of Automotive Fuel Cell.

Proton exchange membrane fuel cells (PEMFCs) for automotive applications suffer from cathode corrosion problems due to the sudden potential jump caused by unintended air leakage into the anodic flow field during start-up and shut-down (SU/SD) events. Here, we report a solution to the instantaneous potential jump issue during SU/SD events by imparting oxygen evolution reaction (OER) activity to the PEMFC cathodic catalyst to preferentially promote OER and suppress the unwanted carbon oxidation reaction at the cathode. In the newly developed Ru-on-Pt/C electrocatalyst, the small particle size of sputtered Ru and the Ru–Pt interaction significantly improve activity–stability for OER and prevent corrosion in cathode by preemptively consuming electrons related to the potential jump. Membrane electrode assemblies constructed using Ru-on-Pt/C showed an extraordinary (98 %) performance retention after repeating the SU/SD protocol test 100 times, demonstrating unprecedented state-of-the-art durability. [Display omitted] • First trial applying Ru to full-cell PEMFC, overcoming instability, protecting cathode via OER. • Unprecedented durability, maintaining 98 % performance after 100 SU/SD cycles. • Implementation of stability improvement effect through size effect of Ru and formation of Ru-Pt bond. • Our approach reduces material cost by minimizing precious metals and using PVD techniques. [ABSTRACT FROM AUTHOR]