English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/197446
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Exportar a otros formatos:

Title

Strain effects on the oxidation of CO and HCOOH on Au-Pd core-shell nanoparticles

AuthorsCelorrio, Verónica; Quaino, Paola; Santos, Elizabeth; Flórez-Montaño, Jonathan; Humphrey, Jo J. L.; Guillén-Villafuerte, O.; Plana, Daniela; Lázaro Elorri, María Jesús ; Pastor Tejera, Elena; Fermin, David J.
KeywordsFormic acid
Au-Pd core-shells
DEMS
In situ FTIR
Strain effect
Issue Date17-Jan-2017
PublisherAmerican Chemical Society
CitationACS Catalysis 7(3): 1673-1680 (2017)
AbstractThe mechanism of CO and HCOOH electrooxidation in an acidic solution on carbon-supported Au–Pd core–shell nanoparticles was investigated by differential electrochemical mass spectrometry and in situ Fourier transform infrared (FTIR) spectroscopy. Analysis performed in nanostructures with 1.3 ± 0.1 nm (CS1) and 9.9 ± 1.1 nm (CS10) Pd shells provides compelling evidence that the mechanism of adsorbed CO (COads) oxidation is affected by structural and electronic effects introduced by the Au cores. In the case of CS10, a band associated with adsorbed OH species (OHads) is observed in the potential range of CO oxidation. This feature is not detected in the case of CS1, suggesting that the reaction follows an alternative mechanism involving COOHads species. The faradaic charge associated with COads oxidation as well as the Stark slope measured from FTIR indicates that the overall affinity and orbital coupling of CO to Pd are weaker for CS1 shells. FTIR spectroscopy also revealed the presence of HCOOads intermediate species only in the case of CS1. This observation allowed us to conclude that the higher activity of CS10 toward this reaction is due to a fast HCOOads oxidation step, probably involving OHads, to generate CO2. Density functional theory calculations are used to estimate the contributions of the so-called ligand and strain effects on the local density of states of the Pd d-band. The calculations strongly suggest that the key parameter contributing to the change in mechanism is the effective lattice strain.
Description8 Figuras, 1 Tabla, 2 Esquemas
Publisher version (URL)http://dx.doi.org/10.1021/acscatal.6b03237
URIhttp://hdl.handle.net/10261/197446
DOIhttp://dx.doi.org/10.1021/acscatal.6b03237
E-ISSN2155-5435
Appears in Collections:(ICB) Artículos
Files in This Item:
File Description SizeFormat 
acscatal.6b03237.pdfArtículo principal6,21 MBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.