Nature of the active site for CO oxidation on highly active Au/γ-Al2O3

C. K. Costello, M. C. Kung, H. S. Oh, Y. Wang, Harold H Kung

Research output: Contribution to journalArticle

277 Citations (Scopus)

Abstract

The deactivation and regeneration phenomenon during room temperature CO oxidation was studied over a Au/γ-Al2O3 catalyst, which was as active as the most active supported Au catalysts reported in the literature. The initial rapid loss of activity could be prevented if either hydrogen or water vapor was present in the reaction mixture. Otherwise, it could be recovered by exposure of the deactivated catalyst to either hydrogen or water vapor at room temperature. Thermal treatment above 100°C in a dry atmosphere also deactivated the catalyst. These results suggested that hydroxyl group, most likely associated with a Au(I) cation, is associated with the active site and support the proposal that the active site is an ensemble of Au+OH- together with Au(0) atoms. The CO oxidation reaction was proposed to proceed via the insertion of CO into the Au+OH- bond to form a hydroxycarbonyl, which is oxidized to a bicarbonate. Decarboxylation of the bicarbonate completes the reaction cycle.

Original languageEnglish
Pages (from-to)159-168
Number of pages10
JournalApplied Catalysis A: General
Volume232
Issue number1-2
DOIs
Publication statusPublished - Jun 10 2002

Fingerprint

Carbon Monoxide
Steam
Bicarbonates
Oxidation
Water vapor
Catalysts
Hydrogen
Catalyst supports
Hydroxyl Radical
Cations
Positive ions
Heat treatment
Atoms
Temperature
hydroxide ion

Keywords

  • Active site
  • Carbon monoxide
  • Oxidation gold

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Nature of the active site for CO oxidation on highly active Au/γ-Al2O3. / Costello, C. K.; Kung, M. C.; Oh, H. S.; Wang, Y.; Kung, Harold H.

In: Applied Catalysis A: General, Vol. 232, No. 1-2, 10.06.2002, p. 159-168.

Research output: Contribution to journalArticle

Costello, C. K. ; Kung, M. C. ; Oh, H. S. ; Wang, Y. ; Kung, Harold H. / Nature of the active site for CO oxidation on highly active Au/γ-Al2O3. In: Applied Catalysis A: General. 2002 ; Vol. 232, No. 1-2. pp. 159-168.
@article{f91072ad668444dfa2e2c59dc5683a5a,
title = "Nature of the active site for CO oxidation on highly active Au/γ-Al2O3",
abstract = "The deactivation and regeneration phenomenon during room temperature CO oxidation was studied over a Au/γ-Al2O3 catalyst, which was as active as the most active supported Au catalysts reported in the literature. The initial rapid loss of activity could be prevented if either hydrogen or water vapor was present in the reaction mixture. Otherwise, it could be recovered by exposure of the deactivated catalyst to either hydrogen or water vapor at room temperature. Thermal treatment above 100°C in a dry atmosphere also deactivated the catalyst. These results suggested that hydroxyl group, most likely associated with a Au(I) cation, is associated with the active site and support the proposal that the active site is an ensemble of Au+OH- together with Au(0) atoms. The CO oxidation reaction was proposed to proceed via the insertion of CO into the Au+OH- bond to form a hydroxycarbonyl, which is oxidized to a bicarbonate. Decarboxylation of the bicarbonate completes the reaction cycle.",
keywords = "Active site, Carbon monoxide, Oxidation gold",
author = "Costello, {C. K.} and Kung, {M. C.} and Oh, {H. S.} and Y. Wang and Kung, {Harold H}",
year = "2002",
month = "6",
day = "10",
doi = "10.1016/S0926-860X(02)00092-3",
language = "English",
volume = "232",
pages = "159--168",
journal = "Applied Catalysis A: General",
issn = "0926-860X",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Nature of the active site for CO oxidation on highly active Au/γ-Al2O3

AU - Costello, C. K.

AU - Kung, M. C.

AU - Oh, H. S.

AU - Wang, Y.

AU - Kung, Harold H

PY - 2002/6/10

Y1 - 2002/6/10

N2 - The deactivation and regeneration phenomenon during room temperature CO oxidation was studied over a Au/γ-Al2O3 catalyst, which was as active as the most active supported Au catalysts reported in the literature. The initial rapid loss of activity could be prevented if either hydrogen or water vapor was present in the reaction mixture. Otherwise, it could be recovered by exposure of the deactivated catalyst to either hydrogen or water vapor at room temperature. Thermal treatment above 100°C in a dry atmosphere also deactivated the catalyst. These results suggested that hydroxyl group, most likely associated with a Au(I) cation, is associated with the active site and support the proposal that the active site is an ensemble of Au+OH- together with Au(0) atoms. The CO oxidation reaction was proposed to proceed via the insertion of CO into the Au+OH- bond to form a hydroxycarbonyl, which is oxidized to a bicarbonate. Decarboxylation of the bicarbonate completes the reaction cycle.

AB - The deactivation and regeneration phenomenon during room temperature CO oxidation was studied over a Au/γ-Al2O3 catalyst, which was as active as the most active supported Au catalysts reported in the literature. The initial rapid loss of activity could be prevented if either hydrogen or water vapor was present in the reaction mixture. Otherwise, it could be recovered by exposure of the deactivated catalyst to either hydrogen or water vapor at room temperature. Thermal treatment above 100°C in a dry atmosphere also deactivated the catalyst. These results suggested that hydroxyl group, most likely associated with a Au(I) cation, is associated with the active site and support the proposal that the active site is an ensemble of Au+OH- together with Au(0) atoms. The CO oxidation reaction was proposed to proceed via the insertion of CO into the Au+OH- bond to form a hydroxycarbonyl, which is oxidized to a bicarbonate. Decarboxylation of the bicarbonate completes the reaction cycle.

KW - Active site

KW - Carbon monoxide

KW - Oxidation gold

UR - http://www.scopus.com/inward/record.url?scp=0037054052&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037054052&partnerID=8YFLogxK

U2 - 10.1016/S0926-860X(02)00092-3

DO - 10.1016/S0926-860X(02)00092-3

M3 - Article

VL - 232

SP - 159

EP - 168

JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

SN - 0926-860X

IS - 1-2

ER -