Author: D. N. Beltyon
Publisher:
ISBN:
Category :
Languages : en
Pages : 29
Book Description
Thin films of Pt, vapor deposited on an oxidized Ti foil, have been utilized as models of high surface area Pt/TiO2 catalysts which show strong metal-support interactions (SMSI). Both fully oxidized (Ti(4+)) and partially reduced (significant amounts of Ti(3+)) surfaces were studied. As a function of Pt coverage, the development of bulk Pt chemisorption characteristics occurs at significantly lower coverages on the oxidized substrate. In particular, at a given Pt coverage there is less chemisorption of both CO and H2 on the reduced, a compared to the oxidized, TiO2 and the desorption spectra peak at lower temperatures. No evidence for significant differences in the chemical state of the Pt is found by XPS and AES. We propose a model, consistent with earlier work on high surface area Pt/TiO2 catalysts, in which the morphology of the Pt on the reduced catalysts is significantly flatter (dominated by (111) terraces) and is slightly modified electronically, as compared to the oxidized sample.
Thin Film Models of SMSI (Show Strong Metal-Support Interactions) Catalysts: Pt on Oxidized Titanium
Author: D. N. Beltyon
Publisher:
ISBN:
Category :
Languages : en
Pages : 29
Book Description
Thin films of Pt, vapor deposited on an oxidized Ti foil, have been utilized as models of high surface area Pt/TiO2 catalysts which show strong metal-support interactions (SMSI). Both fully oxidized (Ti(4+)) and partially reduced (significant amounts of Ti(3+)) surfaces were studied. As a function of Pt coverage, the development of bulk Pt chemisorption characteristics occurs at significantly lower coverages on the oxidized substrate. In particular, at a given Pt coverage there is less chemisorption of both CO and H2 on the reduced, a compared to the oxidized, TiO2 and the desorption spectra peak at lower temperatures. No evidence for significant differences in the chemical state of the Pt is found by XPS and AES. We propose a model, consistent with earlier work on high surface area Pt/TiO2 catalysts, in which the morphology of the Pt on the reduced catalysts is significantly flatter (dominated by (111) terraces) and is slightly modified electronically, as compared to the oxidized sample.
Publisher:
ISBN:
Category :
Languages : en
Pages : 29
Book Description
Thin films of Pt, vapor deposited on an oxidized Ti foil, have been utilized as models of high surface area Pt/TiO2 catalysts which show strong metal-support interactions (SMSI). Both fully oxidized (Ti(4+)) and partially reduced (significant amounts of Ti(3+)) surfaces were studied. As a function of Pt coverage, the development of bulk Pt chemisorption characteristics occurs at significantly lower coverages on the oxidized substrate. In particular, at a given Pt coverage there is less chemisorption of both CO and H2 on the reduced, a compared to the oxidized, TiO2 and the desorption spectra peak at lower temperatures. No evidence for significant differences in the chemical state of the Pt is found by XPS and AES. We propose a model, consistent with earlier work on high surface area Pt/TiO2 catalysts, in which the morphology of the Pt on the reduced catalysts is significantly flatter (dominated by (111) terraces) and is slightly modified electronically, as compared to the oxidized sample.
Strong Metal-support Interactions
Author: R. T. K. Baker
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 258
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 258
Book Description
Scientific and Technical Aerospace Reports
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 784
Book Description
Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 784
Book Description
Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Oxide Materials at the Two-Dimensional Limit
Author: Falko P. Netzer
Publisher: Springer
ISBN: 3319283324
Category : Technology & Engineering
Languages : en
Pages : 403
Book Description
This book summarizes the current knowledge of two-dimensional oxide materials. The fundamental properties of 2-D oxide systems are explored in terms of atomic structure, electronic behavior and surface chemistry. The concept of polarity in determining the stability of 2-D oxide layers is examined, charge transfer effects in ultrathin oxide films are reviewed as well as the role of defects in 2-D oxide films. The novel structure concepts that apply in oxide systems of low dimensionality are addressed, and a chapter giving an overview of state-of-the-art theoretical methods for electronic structure determination of nanostructured oxides is included. Special emphasis is given to a balanced view from the experimental and the theoretical side. Two-dimensional materials, and 2-D oxides in particular, have outstanding behavior due to dimensionality and proximity effects. Several chapters treat prototypical model systems as illustrative examples to discuss the peculiar physical and chemical properties of 2-D oxide systems. The chapters are written by renowned experts in the field.
Publisher: Springer
ISBN: 3319283324
Category : Technology & Engineering
Languages : en
Pages : 403
Book Description
This book summarizes the current knowledge of two-dimensional oxide materials. The fundamental properties of 2-D oxide systems are explored in terms of atomic structure, electronic behavior and surface chemistry. The concept of polarity in determining the stability of 2-D oxide layers is examined, charge transfer effects in ultrathin oxide films are reviewed as well as the role of defects in 2-D oxide films. The novel structure concepts that apply in oxide systems of low dimensionality are addressed, and a chapter giving an overview of state-of-the-art theoretical methods for electronic structure determination of nanostructured oxides is included. Special emphasis is given to a balanced view from the experimental and the theoretical side. Two-dimensional materials, and 2-D oxides in particular, have outstanding behavior due to dimensionality and proximity effects. Several chapters treat prototypical model systems as illustrative examples to discuss the peculiar physical and chemical properties of 2-D oxide systems. The chapters are written by renowned experts in the field.
Physics Briefs
Spectroscopy of Metal/Titania Systems
Author: Y. M. Sun
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Thin film models of catalysts known to show strong metal support interactions were investigated. These consist of vapor-deposited Pt or Rh on Ti02 films prepared in ultrahigh vacuum by oxidation of Ti(000 + or - ). TDS, AES and static SIMS were used to characterize the surfaces before and after thermal treatment in vacuum and with or without chemisorbed C0. The results indicate that heating in vacuum to near 750K leads to migration of a reduced form of titania to the metal film surface, accompanied by suppression of C0 and hydrogen chemisorption. In 1 to 2 ML metal films with no surface titania species, no significant suppression of hydrogen chemisorption is seen, indicating that surface segregation alone is not responsible for the changes in hydrogen chemisorption extent and energetics.
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Thin film models of catalysts known to show strong metal support interactions were investigated. These consist of vapor-deposited Pt or Rh on Ti02 films prepared in ultrahigh vacuum by oxidation of Ti(000 + or - ). TDS, AES and static SIMS were used to characterize the surfaces before and after thermal treatment in vacuum and with or without chemisorbed C0. The results indicate that heating in vacuum to near 750K leads to migration of a reduced form of titania to the metal film surface, accompanied by suppression of C0 and hydrogen chemisorption. In 1 to 2 ML metal films with no surface titania species, no significant suppression of hydrogen chemisorption is seen, indicating that surface segregation alone is not responsible for the changes in hydrogen chemisorption extent and energetics.
Advances in Catalysis
Author:
Publisher: Academic Press
ISBN: 0080565409
Category : Technology & Engineering
Languages : en
Pages : 409
Book Description
Advances in Catalysis
Publisher: Academic Press
ISBN: 0080565409
Category : Technology & Engineering
Languages : en
Pages : 409
Book Description
Advances in Catalysis
Government reports annual index
Government Reports Annual Index: Keyword A-L
Author:
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1092
Book Description
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1092
Book Description