‫شر ال ع لميمرك ز ال ن‬
Center of Scientific Publications













MainPage
About the center
Journal of KAU
Electronic books
Saudi Systems
Search for Publications
Parallel Publication
Researches
Files
New Publications
Publications
o Scientific books
 Islamic
economy
 Economy and
administration
 Literature
 Reviews
 Geography
 Computer
Science
 Fire
 Religion
 Mathematics
and Statistics
 Geology
 Piology
 Educational
Science
o Seminars and
Conferences
o Training Courses
o Official Printing on
Paper
o Abstracts and indexes
Under publishing
Request
o Request Order
o Subscription
‫جامعة ال م لك ع بدال عزي ز‬
King Abdulaziz University
Document Details
Document Type
Document Title
: Article In Conference
: Catalyst deactivation in preferential oxidation
of CO in H2-rich streams over Au/CeO2Co3O4
Catalyst deactivation in preferential oxidation
of CO in H2-rich streams over Au/CeO2Co3O4
Subject
Document
Language
Abstract
: ‫ءك يم يا‬
: English
: Gold catalysts have drawn much attention due
to their excellent performance in many
reactions, especially in low temperature CO
oxidation and CO preferential oxidation
(PROX) in H2-rich stream for proton exchange
membrane fuel cells (PEMFC). However,
catalyst deactivation is still a critical issue for
long-term operation, while detailed
investigation in deactivation mechanism is
insufficient [1]. Schumacher et al. reported that
the accumulation of carbonate and formate was
responsible for the deactivation of Au/TiO2 for
low temperature CO oxidation in H2-free
stream, while the accumulation of water
byproduct caused the deactivation in H2-rich
stream [2]. Steyn et al. suggested that the
deactivation of Au/TiO2 for CO PROX may be
a result of the intrinsic transformation in
oxidation state of active species under the
reducing reaction stream [3]. Recently, we
reported a novel catalyst Au/CeO2-Co3O4 for
CO PROX prepared by depositionprecipitation. The catalyst exhibits much higher
catalytic activity than Au/Co3O4 and
Au/CeO2; 100% CO conversion with 75%

Contact Us
Visits Of this Page
0
Conference Name
selectivity to CO2 can be achieved even at
ambient temperature. The Au/CeO2-Co3O4
catalyst (Ce/Co = 0.2) was investigated with
respect to its stability for CO PROX in H2-rich
streams at 80 oC; a gradual decrease of activity
was observed after the operation lasted for 260
h [4]. In this work, to investigate the catalyst
deactivation in detail, the fresh and deactivated
Au/CeO2-Co3O4 catalysts for CO PROX were
characterized by HRTEM, XPS, H2-TPR,
DRIFTS, and O2-TPO. The HRTEM images
show that Au particles are still highly dispersed
after the reaction, suggesting that an
aggregation or sintering of Au particles may be
excluded from the causes of catalyst
deactivation. The XPS results reveal that both
ionic and metallic gold are present in the fresh
samples, while only metallic gold exists in the
deactivated catalyst. H2-TPR demonstrates a
change in reductive properties of the catalysts
during the reaction. The accumulation of
carbonate and formate on the surface of the
catalyst is confirmed by both DRIFTS of CO
adsorption and O2-TPO. Furthermore, the in
situ DRIFTS under reaction conditions
demonstrate the accumulation of water
byproduct on the catalyst surface during the
reaction process. Therefore, it was proposed
that the deactivation of Au/CeO2-Co3O4 for
CO PROX in H2-rich streams may be
originated from both the change of gold
oxidation state and the accumulation of the
carbonate-like species and water byproducts on
the catalyst surface. [1] G.C. Bond, C. Louis,
D.T. Thompson, Catalysis by Gold, Imperial
College Press, London, 2006. [2] B.
Schumacher, V. Plzak, M. Kinne, R.J. Behm,
Catal. Lett. 89 (2003) 109. [3] J. Steyn, G.
Pattrick, M.S. Scurrell, D. Hildebrandt, M.C.
Raphulu, E. van der Lingen, Catal. Today 122
(2007) 254. [4] H. Wang, H.Q. Zhu, Z.F. Qin,
G.F. Wang, F.X. Liang, J.G. Wang, Catal.
Commun. 9 (2008) 1487.
: Tenth International Symposium on
Heterogeneous Catalysis
Duration
Publishing Year
Article Type
Added Date
: From : 22/8/1429 AH - To : 26/8/1429 AH
From : 23/8/2008 AD - To : 27/8/2008 AD
: 1429 AH
2008 AD
: Article
: Saturday, February 14, 2009
Researchers
Researcher Name Researcher Name Researcher
Dr
Email
(Arabic)
(English)
Type
Grade
Hui Wang
Hui Wang
Researcher Doctorate
Huaqing Zhu
Huaqing Zhu
Researcher Doctorate
Zhangfeng Qin
Zhangfeng Qin
Researcher Doctorate
Feixue Liang
Feixue Liang
Researcher Doctorate
Guofu Wang
Guofu Wang
Researcher Doctorate
Jianguo Wang
Jianguo Wang
Researcher Doctorate
Files
File Name
18261.pdf
Type
pdf
Deanship of Information Technology - King Abdulaziz University. All rights reserved
Description