In order to examine the relationship between the oxygen reduction reaction (ORR) activity of a fuel cell catalyst and its structure and/or electronic state, carbon-supported Pt and Pt alloys having various structures, compositions, and morphologies were studied. Regardless of the atomic ordering or morphology (core−shell or random alloy) of the catalyst, the ORR activity was primarily dependent on the Pt−Pt bond distance. Among these materials, Pt 2 Co, having the shortest Pt−Pt distance, exhibited the highest ORR activity. The activities of this catalyst per unit surface area and per unit mass were approximately 10 times and 6 times higher than those of a commercially available carbon supported Pt electrocatalyst (Pt/C). This work also found a monotonic increase in catalytic activity with decreasing Pt−Pt distance.
A carbon-supported Pt-shell Au-core
electrocatalyst (Pt/Au/C) was
prepared by sequential deposition of Pt ions on the surface of Au
nanoparticles supported on carbon. The area-specific activity of the
oxygen reduction reaction (ORR) for the prepared Pt/Au/C in 0.1 M
HClO4 aqueous solution was approximately 2 times higher
than that for a commercial carbon-supported Pt electrocatalyst (Pt/C).
The core–shell structure was confirmed using electrochemical
methods and Pt and Au K-edge X-ray absorption fine structure (XAFS)
analysis. XAFS analyses indicated that the Pt–Pt bond distance
for the Pt/Au/C catalyst was shorter than that for Pt foil and the
Pt/C catalyst. In addition, the Au–Au distance was much shorter
than that for Au foil. The reason for the high ORR activity of Pt/Au/C
is considered to be shorter Pt–Pt bond distance as compared
to that of Pt/C.
Reduction of Pt loading on fuel cell electric vehicles is strongly desired for fuel cell electric vehicles to be commercially viable. Activity enhancement for the sluggish oxygen reduction reaction of Pt-based electrocatalyst is the most essential to reduce Pt loading. Here, we provide a brief review of recent advances in Pt-based ORR electrocatalysts followed by electrocatalyst research activities of Nissan.
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.