Abstract
This study shows that the predominant degradation mechanism of Pt/Vulcan XC72 electrocatalysts strongly depends on the nature of the gas atmosphere and of the upper potential limit used in accelerated stress tests (ASTs). The morphological changes of Pt/Vulcan XC72 nanoparticles were studied by identical location transmission electron microscopy (IL-TEM), following accelerated stress tests in different potential ranges and under various gas atmospheres. X-ray photoelectron spectroscopy was used to probe changes in carbon surface chemistry. Whereas minor changes were detected under neutral atmosphere (Ar) and low potential limit conditions (0.05<E<0.50V vs. RHE), the migration/aggregation of Pt nanocrystallites was strongly accelerated in the presence of a reducing atmosphere, such as CO. Carbon corrosion and Pt nanoparticle detachment were more frequently observed under oxidizing atmosphere (O2). With an increase of the upper potential limit to 1.23V vs. RHE, the trends observed previously were maintained but 3D Ostwald ripening strongly overlapped with the three other degradation mechanisms, precluding any identification of the dominant mechanism.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
