• Probing the Surface Structure...

Treffer: Probing the Surface Structure of α-Mn2O3 Nanocrystals during CO Oxidation by Operando Raman Spectroscopy

Title:
Probing the Surface Structure of α-Mn2O3 Nanocrystals during CO Oxidation by Operando Raman Spectroscopy
Authors:
YAN LUO, DENG, Ya-Qing, WEI MAO, YANG, Xue-Jing, KAKE ZHU, JING XU, HAN, Yi-Fan
Source:
Journal of physical chemistry. C. 116(39):20975-20981
Publisher Information:
Columbus, OH: American Chemical Society, 2012.
Publication Year:
2012
Physical Description:
print, 28 ref
Original Material:
INIST-CNRS
Subject Terms:
General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Nanopoudres, Nanopowders, Méthodes de nanofabrication, Methods of nanofabrication, Autoassemblage, Self-assembly, Terre, ocean, espace, Earth, ocean, space, Astronomie, Astronomy, Systèmes stellaires. Objets et systèmes galactiques et extragalactiques. L'univers, Stellar systems. Galactic and extragalactic objects and systems. The universe, Divers, Other topics on stellar systems; galactic and extragalactic objects and systems; the universe, Autoassemblage, Self-assembly, Calcination, Coadsorption, Coadsorción, Dépendance température, Temperature dependence, Effet température, Temperature effects, Etirement, Stretching, Estiramiento, Haute température, High temperature, Alta temperatura, Microstructure, Morphologie, Morphology, Nanocristal, Nanocrystal, Nanomatériau, Nanostructured materials, Oxydation, Oxidation, Précurseur, Precursor, Reconstruction surface, Surface reconstruction, Spectrométrie Raman, Raman spectroscopy, Structure surface, Surface structure, Synthèse nanomatériau, Nanomaterial synthesis, Síntesis nanomaterial, TDS, Température surface, Surface temperature, Transformation phase surface, Surface phase transformations, Transformation phase, Phase transformations, 8107W, 8116D, MnO
Time:
9865
Document Type:
Fachzeitschrift Article
File Description:
text
Language:
English
Author Affiliations:
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
ISSN:
1932-7447
Access URL:
http://pascal-francis.inist.fr/vibad/index.php?action=search&terms=26443207
Rights:
Copyright 2014 INIST-CNRS
CC BY 4.0
Sauf mention contraire ci-dessus, le contenu de cette notice bibliographique peut être utilisé dans le cadre d’une licence CC BY 4.0 Inist-CNRS / Unless otherwise stated above, the content of this bibliographic record may be used under a CC BY 4.0 licence by Inist-CNRS / A menos que se haya señalado antes, el contenido de este registro bibliográfico puede ser utilizado al amparo de una licencia CC BY 4.0 Inist-CNRS
Notes:
Astronomy

Physics and materials science
Accession Number:
edscal.26443207
Database:
PASCAL Archive

Weitere Informationen

The α-Mn2O3 nanocrystals with uniform morphology prepared by calcining a self-assembly Mn3O4 precursor show higher activity toward CO oxidation. Operando Raman spectroscopy is used to probe the near-surface structure of α-Mn2O3 nanocrystals during the adsorption and oxidation of CO for the first time. A surface phase-transformation from α-Mn2O3 to MnO-like species, as evidenced by the formation of a single band at 498 cm-', was observed only at or above 300 °C in the presence of CO. This modification is probably due to the loss of lattice oxygen at high temperatures that leads to the surface reconstruction. Very interestingly, a reversible phase-transformation was observed with decreasing the temperature to 25 °C. The shift of the symmetric stretching of Mn2O3 goups (632 → 649 cm―1) due to the adsorption of CO was observed even at room temperature. In addition, the results of the temperature-programmed desorption of O2 (TPD-O2) and temperature-programmed surface reaction (TRSR) indicate that the oxidizing of CO may proceed through the Langmuir― Hinshelwood mechanism (<220 °C) to Mars-van-Krevelen mechanism (>350 °C) with the increasing of reaction temperature. In particular, the weakly adsorbed oxygen is deduced to be responsible for CO oxidation at low temperatures.