Oleylamine aging of PtNi nanoparticles giving enhanced functionality for the oxygen reduction reaction

Journal article

We report a rapid solution-phase strategy to synthesize alloyed PtNi nanoparticles which demonstrate outstanding functionality for the oxygen reduction reaction (ORR). This one-pot coreduction colloidal synthesis results in a monodisperse population of single-crystal nanoparticles of rhombic dodecahedral morphology with Pt-enriched edges and compositions close to Pt1Ni2. We use nanoscale 3D compositional analysis to reveal for the first time that oleylamine (OAm)-aging of the rhombic dodecahedral Pt1Ni2 particles results in Ni leaching from surface facets, producing aged particles with concave faceting, an exceptionally high surface area, and a composition of Pt2Ni1. We show that the modified atomic nanostructures catalytically outperform the original PtNi rhombic dodecahedral particles by more than two-fold and also yield improved cycling durability. Their functionality for the ORR far exceeds commercially available Pt/C nanoparticle electrocatalysts, both in terms of mass-specific activities (up to a 25-fold increase) and intrinsic area-specific activities (up to a 27-fold increase).

Authors: Leteba, GM; Wang, Y-C; Slater, TJA; Cai, R; Byrne, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Nano Letters
• Volume: 21
• Issue: 9
• Pages: 3989-3996
• Publication date: 2021-04-26
• Acceptance date: 2021-03-25
• DOI: 10.1021/acs.nanolett.1c00706
• EISSN: 1530-6992
• ISSN: 1530-6984
• Pmid: 33899489
• Language: English
• Keywords: ORR; nanoparticle; electron tomography; FFR; PEMFC; STEM-EDS; electrocatalyst