Recent performance and cost studies predict that the high PGM loadings in the electrodes of today's direct hydrogen fuel cells will prove a limiting factor in their commercial viability for automotive applications.Significant breakthroughs in electrocatalyst technology yielding materials with high activity, low cost and good durability are required. This paper reports on a collaborative effort which has focussed on the exciting core-shell oxygen reduction catalysts pioneered by Brookhaven National Laboratory. These materials promise high catalyst activity and PGM thrifting although to date, are typically fabricated by in-situ electrochemical techniques. Following the development of scalable syntheses, extensive catalyst characterisation methods have been employed to analyse and verify the success of a scaled Pt ML /Pd 3 Co/C catalyst. Although synthetic challenges remain, the scaled core-shell materials yield RDE activities of 0.72 A/mg Pt constituting an impressive 3.7x improvement in Pt activity relative to Pt/C and exceeding the 0.44 A/mg Pt automotive target.
Pt and Pt alloy catalysts for the PEMFC cathode fall short of the high activities per gram of Pt required to enable large scale automotive PEMFC commercialization. Thrifting of the active Pt component in the ORR catalyst via the formation of core shell catalysts is an exciting approach to resolve this issue. Pt monolayers have been deposited onto Pd3Co, Pd3Fe and Ir cores using scaleable proprietary methods. Characterisation of these materials, via cyclic voltammetry, LEIS and XPS, showed successful Pt coating of the surface and enhanced catalyst stability in liquid electrolyte cycling tests compared to the bare cores. Electrolyte analysis indicated leaching of base metals and Pd/Ir, so further optimisation is required to generate a uniform pinhole free Pt shell. RDE testing showed 3.7 x Pt activity for PtML/Pd3Co and preliminary MEA tests show great promise, with mass activity up to 2 x that of Pt only.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.