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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Electrocatalytic activity of platinum nanoparticles supported on different phases of tungsten carbides for the oxygen reduction reaction

Full text
Author(s):
Bott-Neto, Jose L. ; Beck, Jr., Watson ; Varanda, Laudemir C. ; Ticianelli, Edson A.
Total Authors: 4
Document type: Journal article
Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 42, n. 32, p. 20677-20688, AUG 10 2017.
Web of Science Citations: 10
Abstract

Carbon-supported tungsten carbides with cubic (beta-WC1-X/C) and hexagonal (alpha-WC/C) are evaluated as support materials of Pt-nanoparticles, to be used as electrocatalysts for the oxygen reduction reaction (ORR) in acid media. The produced materials are characterized by X -Ray diffraction (XRD), energy dispersive X-ray spectroscopy, (EDS), X-ray photoelectron spectroscopy (XPS), in situ X-ray absorption near edge structure (XANES), and transmission electron microscopy (TEM). Cyclic voltammetry and polarization measurements on stationary and rotation disk electrodes are employed for the electrochemical investigations. It is seen that all Pt-alpha-WC/C catalysts present specific activity for the ORR similar to that of a standard carbon supported Pt catalyst (Pt/C), while for the Pt-beta-WC1-X/C composites the specific activitiy is 3.6 times higher than that of Pt/C, when a carbide-to carbon load of 40 wt% is used. These differences in reactivity for the ORR may be associated to differences in the binding energy of adsorbed oxygen on Pt, introduced by the tungsten carbide substrates. Pt XANES results for the beta-WC/C1-x materials evidence a small increase in the Pt 5d band occupancy, which may lead to a weaker Pt-OHX. interaction, increasing the ORR kinetics. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
Grantee:Edson Antonio Ticianelli
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 13/01284-2 - Theranostic nanoparticles based in superparamagnetic iron oxide for skin cancer therapy by magnetic hyperthermia
Grantee:Laudemir Carlos Varanda
Support Opportunities: Regular Research Grants