Synthesis of PtNi Nanoparticles to Accelerate the Oxygen Reduction Reaction

Authors

Gerard M. Leteba, University of Cape Town
Sarah L. George, University of Cape Town
David R.G. Mitchell, University of Wollongong
Pieter B.J. Levecque, University of Cape Town
Eric van Steen, University of Cape Town
Lebohang Macheli, University of South Africa
Candace I. Lang, University of Cape Town

Publication Name

ChemPlusChem

Abstract

We report the synthesis of core-shell Ni−Pt nanoparticles (NPs) with varying degrees of crystallographic facets and surface layers rich in Pt via a seed-mediated thermolytic approach. Mixtures of different surfactants used during synthesis resulted in preferential surface passivation, which in turn dictated the size, chemical composition, and geometric evolution of these PtNi NPs. Electrochemical investigations of these pristine core-shell Ni−Pt structures in the oxygen reduction reaction (ORR) show that their catalytic functionalities outperform the commercial Pt/C reference catalyst. The enhanced electrocatalytic ORR performances of these Pt-based PtNi NPs are correlated with the weakened oxygen binding strength or surface-adsorbed hydroxyl (OH) species on active Pt surface sites induced by the downshift of the d-band center as a result of compressive strain effects. Our studies offer a robust synthetic approach for the development of core-shell nanostructures for enhanced ORR catalysis.

Open Access Status

This publication may be available as open access