Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/242451
Type: Artigo
Title: Alloying tungsten carbide nanoparticles with tantalum: impact on electrochemical oxidation resistance and hydrogen evolution activity
Author: Hunt, Sean T.
Kokumai, Tathiana Midori
Zanchet, Daniela
Roman-Leshkov, Yuriy
Abstract: Metal-terminated bimetallic carbide nanoparticles (NPs) of tungsten and tantalum are synthesized in a monodisperse particle size distribution of 2-3 nm. The bimetallic particles feature enhanced electrocatalytic behavior with respect to the monometallic composition. X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements indicate that the Ta0.3W0.7C NPs consist of a well-mixed random alloy featuring a compressed lattice that favorably impacts stability and catalytic activity. Electrochemical testing shows that the incorporation of 30% tantalum into the tungsten carbide lattice increases the electrochemical oxidation resistance of the NPs. The onset of surface passivation in 0.5 M H2SO4 shifted from +0.2 V vs RHE to +0.45 V vs RHE, and the maximum surface oxidation current shifted from +0.4 to +0.75 V vs RHE. The activity toward hydrogen evolution (HER) of the carbon-supported Ta0.3W0.7C NPs is preserved relative to the activity of unmodified carbon-supported WC NPs. The increase in electrochemical oxidation resistance is attributed to the presence of surface Ta moieties as determined by X-ray photoelectron spectroscopy (XPS) while the preservation of the HER activity is attributed to the observed lattice compression.
Metal-terminated bimetallic carbide nanoparticles (NPs) of tungsten and tantalum are synthesized in a monodisperse particle size distribution of 2–3 nm. The bimetallic particles feature enhanced electrocatalytic behavior with respect to the monometallic c
Subject: Carbonetos
Nanopartículas
Eletrocatálise
Oxidação
Compostos de metais de transição
Estabilidade
Country: Estados Unidos
Editor: American Chemical Society
Citation: Alloying Tungsten Carbide Nanoparticles With Tantalum: Impact On Electrochemical Oxidation Resistance And Hydrogen Evolution Activity. Amer Chemical Soc, v. 119, p. 13691-13699 Jun-2015.
Rights: fechado
Identifier DOI: 10.1021/acs.jpcc.5b02922
Address: https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.5b02922
Date Issue: 2015
Appears in Collections:IQ - Artigos e Outros Documentos

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