Noble metal segregation and cluster size of Pt/Rh/CeO2/γ-Al2O3 automotive three-way catalysts studied with low-energy ion scattering

被引：24
作者：
Jansen, WPA
Harmsen, JMA
von der Gon, AWD
Hoebink, JHBJ
Schouten, JC
Brongersma, HH
机构：
[1] Calipso LEIS Expertise Ctr, NL-5600 MB Eindhoven, Netherlands
[2] Eindhoven Univ Technol, Schuit Inst Catalysis, NL-5600 MB Eindhoven, Netherlands
[3] Eindhoven Univ Technol, Lab Chem Reactor Engn, NL-5600 MB Eindhoven, Netherlands
来源：
JOURNAL OF CATALYSIS | 2001年 / 204卷 / 02期
关键词：
automotive catalysis; cluster size; nanocluster; segregation; LEIS; ISS;
D O I：
10.1006/jcat.2001.3391
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
A method for determining the average cluster size of supported catalysts using low-energy ion scattering (LEIS) data is presented. The method is particularly suitable for determining the average cluster size of atomically dispersed metals and can be used for clusters as large as 10 nm. For Pt/gamma -Al2O3 quantitative agreement is shown between the average cluster size as determined with LEIS and that determined with transmission electron microscopy (TEM). In the case of three-way catalysts, classic methods for determining the cluster size, such as TEM or CO chemisorption, often fail or produce ambiguous results because of the presence of ceria. Therefore, LEIS has been applied to determine the average noble metal cluster size of a commercial three-way catalyst. Moreover, it is shown by LEIS that the three-way catalyst contains mixed Pt/Rh clusters, which are strongly enriched in surface Pt after reduction. (C) 2001 Elsevier Science.
引用
收藏
页码：420 / 427
页数：8
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