화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.37, No.15, 11268-11275, 2012
CO tolerance of nano-architectured Pt-Mo anode electrocatalysts for PEM fuel cells
PEM fuel cell membrane electrode assemblies with Nafion electrolytes and commercial Pt-based cathodes were tested with Pt0.8Mo0.2 alloy and MoOx@Pt core-shell anode electrocatalysts for CO tolerance and short-term stability to corroborate earlier thin-film RDE results. Polarization curves at 70 degrees C for the Pt0.8Mo0.2 alloy in H-2 with 25-1000 ppm CO showed a significant increase in CO tolerance based on peak power densities in comparison to PtRu electrocatalysts. MoOx@Pt core-shell electrocatalysts, which showed extremely high activity for H-2 in 1000 ppm CO during RDE studies, performed relatively poorly in comparison to the Pt0.8Mo0.2 and PtRu alloys for the same total catalyst loading on a per area basis in MEA testing. The discrepancy is attributed to residual stabilizer from the core-shell synthesis impacting catalyst-ionomer interfaces. Nonetheless, the MoOx@Pt electrochemical performance is superior on a per-gram-of-precious-metal basis to the Pt0.8Mo0.2 electrocatalyst for CO concentrations below 100 ppm. Due to cross-membrane Mo migration, the stability of the Mo-containing anode electrocatalysts remains a challenge for developing stable enhanced CO tolerance for low-temperature PEM fuel cells. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.