| Full text | |
| Author(s): |
Total Authors: 4
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| Affiliation: | [1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Fed Abc, Ctr Engn Modelagem & Ciencias Sociais Aplicada, BR-09210170 Santo Andre, SP - Brazil
Total Affiliations: 2
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| Document type: | Journal article |
| Source: | APPLIED CATALYSIS B-ENVIRONMENTAL; v. 136, p. 351-360, JUN 5 2013. |
| Web of Science Citations: | 56 |
| Abstract | |
Pt-based hollow nanoparticles were investigated as electrocatalysts for the oxygen reduction reaction (ORR) in acid electrolyte. The electrocatalysts were synthesized via Ni or Co diffusion/dissolution, induced by the vacancy-mediated Kirkendall effect, during electrochemical potential cycling of Ni@Pt and Co@Pt core-shell nanoparticles in acid media. The nanoparticles were characterized by high resolution transmission electron microscopy, in situ X-ray absorption spectroscopy and X-ray diffraction measurements. The results show substantial differences in nanoparticle structure/composition and in the activity for the ORR, depending on the nature of the non-noble metal in the nanoparticle core. The Pt hollow nanostructures showed higher specific catalytic activity than that of the state-of-the-art Pt/C electrocatalyst. This was attributed to three main effects: (i) hollow-induced lattice contraction in the multilayer Pt shells, (ii) mismatch-induced lattice contraction of the thick Pt shell by the remaining Ni or Co atoms and (iii) a ligand effect, due to the electronic interaction of Pt with the remaining Ni or Co atoms in the Pt multilayers of the hollow structure. These three effects caused a Pt d-band center down-shift, which decreased the adsorption strength of oxygenated reaction intermediates and spectators, thus increasing the ORR rate. (C) 2013 Elsevier B.V. All rights reserved. (AU) | |
| FAPESP's process: | 11/50727-9 - Development of systems for hydrogen production and for the generation and utilization of electrochemical energy |
| Grantee: | Ernesto Rafael Gonzalez |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 09/07629-6 - Electrocatalysis IV: fundamental and applied aspects of electrocatalytic processes, bio-electrocatalysis and kinetic instabilities |
| Grantee: | Edson Antonio Ticianelli |
| Support Opportunities: | Program for Research on Bioenergy (BIOEN) - Thematic Grants |
| FAPESP's process: | 09/11073-3 - Investigation of the mechanism of ethanol electro-oxidation on metallic nanoparticles. |
| Grantee: | Daniel Augusto Cantane |
| Support Opportunities: | Scholarships in Brazil - Doctorate |