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High performance layer-by-layer Pt₃Ni(Pt-skin)-modified Pd/C for the oxygen reduction reaction.

ABSTRACT: Bimetallic Pt-Ni with Pt on the outermost layer and an innermost layer enriched in Ni, referred to as Pt₃Ni(Pt-skin), is a promising configuration of an electrocatalyst for the oxygen reduction reaction (ORR) in fuel cells. We prepare a core (Pd)/shell (Pt₃Ni(Pt-skin)) catalyst (Pt₃Ni(Pt-skin)/Pd/C) from Zn underpotential deposition (UPD) on a Ni UPD modified Pd/C catalyst, facilitating Pt atomic layer-by-layer growth on the Ni surface through the galvanic replacement process. Pt₃Ni(Pt-skin)/Pd/C shows the best ORR performance, with a Pt specific activity of 16.7 mA cm^-2 and Pt mass activity of 14.2 A mg_Pt^-1, which are 90- and 156- fold improvements over commercial Pt/C catalysts. The Pt₃Ni(Pt-skin) structure effectively inhibits Ni leaching to improve the durability in two accelerated durability test modes mimicking the catalyst lifetime and start-up/shut-down cycles.

SUBMITTER: Huang JF

PROVIDER: S-EPMC6053971 | biostudies-literature |

REPOSITORIES: biostudies-literature

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