Platinum nanoparticles supported on nitrogen-doped carbon for ammonia electro-oxidation

Author(s)

Ribeiro, Vilmaria A. ^[1] ; de Freitas, Isabel C. ^[1] ; Neto, Almir O. ^[1] ; Spinace, Estevam V. ^[1] ; Silva, Julio Cesar M. ^[1]

Affiliation

^[1] IPEN CNEN SP, Inst Pesquisas Energet & Nucl, Av Prof Lineu Prestes, 2242 Cidade Univ, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Materials Chemistry and Physics; v. 200, p. 354-360, OCT 1 2017.
• Web of Science Citations: 4

Abstract

Pt nanoparticles supported on carbon (Pt/C) and nitrogen-doped carbon (Pt/NC) were prepared by an alcohol-reduction process and used for ammonia electro-oxidation in alkaline media. Nitrogen-doped carbons were prepared by thermal treatment of urea and Carbon Vulcan XC72 at 800 degrees C under argon atmosphere. The obtained materials showed the presence of face centered cubic structure of Pt and mean particle sizes in the range of 3-3.7 nm. X-ray photoelectron spectroscopy results revealed that Pt/NC 5 (carbon prepared with 5% of urea) presents more Pt on the surface than Pt/C, and the nanoparticles are predominantly in the metallic state. The electrocatalytic activity was investigated by cyclic voltammetry and chronoamperometry experiments. Pt/NC materials showed a higher electrocatalytic activity for ammonia electro-oxidation than Pt/C, whereby the material Pt/NC 5 showed the peak current density 161% higher than Pt/C. The increase of activity might be related to the high electrochemically accessible area of Pt/NC and the improvement on the interaction with water due to the nitrogen onto the support which could contribute to the oxidation of intermediate products from ammonia electro-oxidation. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/09087-4 - Studies on the use of bioethanol in proton exchange membrane and solid oxide fuel cells
• Grantee: Marcelo Linardi
• Support Opportunities: Research Projects - Thematic Grants