Effects of reduction temperature and metal-support interactions on the catalytic activity Pt/γ-Al2O3 and Pt/TiO2 for the oxidation of CO in the presence and absence of H2

被引:168
作者
Alexeev, OS
Chin, SY
Engelhard, MH
Ortiz-Soto, L
Amiridis, MD [1 ]
机构
[1] Univ S Carolina, Dept Chem Engn, Columbia, SC 29208 USA
[2] Pacific NW Natl Lab, WR Riley Environm Mol Sci Lab, Richland, WA 99352 USA
关键词
D O I
10.1021/jp054888v
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
TiO2- and gamma-Al2O3-supported Pt catalysts were characterized by HRTEM, XPS, EXAFS, and in situ FTIR spectroscopy after activation at various conditions, and their catalytic properties were examined for the oxidation of CO in the absence and presence of H-2 (PROX). When gamma-Al2O3 was used as the support, the catalytic, electronic, and structural properties of the Pt particles formed were not affected substantially by the pretreatment conditions. In contrast, the surface properties and catalytic activity of Pt/TiO2 were strongly influenced by the pretreatment conditions. In this case, an increase in the reduction temperature led to higher electron density on Pt, altering its chemisorptive properties, weakening the Pt-CO bonds, and increasing its activity for the oxidation of CO. The in situ FTIR data suggest that both the terminal and bridging CO species adsorbed on fully reduced Pt are active for this reaction. The high activity of Pt/TiO2 for the oxidation of CO can also be attributed to the ability of TiO2 to provide or stabilize highly reactive oxygen species at the metal-support interface. However, such species appear to be more reactive toward H-2 than CO. Consequently, Pt/TiO2 shows substantially lower selectivities toward CO oxidation under PROX conditions than Pt/gamma-Al2O3.
引用
收藏
页码:23430 / 23443
页数:14
相关论文
共 75 条
[1]  
ALEKSEEV OS, 1992, USP KHIM+, V61, P765
[2]   EXAFS characterization of supported metal-complex and metal-cluster catalysts made from organometallic precursors [J].
Alexeev, O ;
Gates, BC .
TOPICS IN CATALYSIS, 2000, 10 (3-4) :273-293
[3]   MgO-supported platinum-tungsten catalysts prepared from organometallic precursors: Platinum clusters isolated on dispersed tungsten [J].
Alexeev, O ;
Shelef, M ;
Gates, BC .
JOURNAL OF CATALYSIS, 1996, 164 (01) :1-15
[4]   Temperature-programmed desorption of hydrogen from platinum particles on γ-Al2O3:: Evidence of platinum-catalyzed dehydroxylation of γ-Al2O3 [J].
Alexeev, O ;
Kim, DW ;
Graham, GW ;
Shelef, M ;
Gates, BC .
JOURNAL OF CATALYSIS, 1999, 185 (01) :170-181
[5]   Partially decarbonylated tetrairidium clusters on γ-Al2O3:: Structural characterization and catalysis of toluene hydrogenation [J].
Alexeev, O ;
Panjabi, G ;
Gates, BC .
JOURNAL OF CATALYSIS, 1998, 173 (01) :196-209
[6]   Effects of adsorbates on supported platinum and iridium clusters: Characterization in reactive atmospheres and during alkene hydrogenation catalysis by X-ray absorption spectroscopy [J].
Alexeev, OS ;
Li, F ;
Amiridis, MD ;
Gates, BC .
JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (06) :2338-2349
[7]   Observation of ligand effects during alkene hydrogenation catalysed by supported metal clusters [J].
Argo, AM ;
Odzak, JF ;
Lai, FS ;
Gates, BC .
NATURE, 2002, 415 (6872) :623-626
[8]  
ATKINS PW, 1998, PHYS CHEM, pCH28
[9]   CARBON-MONOXIDE ADSORPTION ON A PT80FE20(111) SINGLE-CRYSTAL ALLOY [J].
ATLI, A ;
ABON, M ;
BECCAT, P ;
BERTOLINI, JC ;
TARDY, B .
SURFACE SCIENCE, 1994, 302 (1-2) :121-125
[10]  
Baker RT, 2004, NANOSTRUCT SCI TECHN, P403