In-situ polarization-dependent total-reflection fluorescence XAFS studies on the structure transformation of Pt clusters on alpha-Al2O3(0001)

被引：41

作者：

Asakura, K

Chun, WJ

Shirai, M

Tomishige, K

Iwasawa, Y

机构：

[1] UNIV TOKYO,GRAD SCH ENGN,DEPT APPL CHEM,BUNKYO KU,TOKYO 113,JAPAN

[2] TOHOKU UNIV,INST CHEM REACT SCI,SENDAI,MIYAGI 98077,JAPAN

[3] UNIV TOKYO,GRAD SCH ENGN,DEPT CHEM,BUNKYO KU,TOKYO 113,JAPAN

[4] UNIV TOKYO,FAC SCI,RES CTR SPECTROCHEM,BUNKYO KU,TOKYO 113,JAPAN

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 1997年 / 101卷 / 28期

关键词：

D O I：

10.1021/jp970394p

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：

Structures of Pt species derived from Pt-4(mu-CH3COO)(8) on an alpha-Al2O3(0001) single-crystal surface were studied by means of in-situ polarization-dependent total reflection fluorescence XAFS (EXAFS and XANES) techniques. The Pt-4 cluster framework was destroyed upon the deposition of Pt-4(mu-CH3COO)(8) by the reaction on the alpha-Al2O3 surface at room temperature. The isolated Pt species were converted to one-atomic layer thick Pt rafts with the Pt-Pt distance of 0.273 nm when the cluster was treated with H-2 at 373 K. The raftlike Pt clusters were stabilized by the formation of direct Pt-O-Al bonding with the alpha-Al2O3 surface. The raftlike Pt clusters were redispersed to isolated oxidized Pt species by the reaction with NO. They were also transferred to three-dimensional Pt particles by reduction with H-2 at 773 K.

引用

页码：5549 / 5556

页数：8

共 54 条

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