CO dissociation at elevated pressures on supported Pd nanoclusters

被引：62

作者：

Ozensoy, E ^{[1
]}

Min, BK ^{[1
]}

Santra, AK ^{[1
]}

Goodman, DW ^{[1
]}

机构：

[1] Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2004年 / 108卷 / 14期

关键词：

D O I：

10.1021/jp030928o

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：

In-situ polarization modulation infrared reflection absorption spectroscopy (PM-IRAS) is used to study CO adsorption at elevated pressures and temperatures on Pd nanoclusters deposited on crystalline SiO2 thin films. The PM-IRAS data indicate that CO dissociates on the Pd nanoclusters at 185 mbar and at temperature >600 K. Combined STM and PM-IRAS data show that the Pd nanoclusters are three-dimensional and consist predominantly of <111> facets with an average diameter and height of 3.5 and 0.7 nm, respectively. STM data indicate no change in the morphology or sintering of the Pd nanoclusters between 300 and 650 K. For comparison, CO adsorption was investigated on a Pd(111) single-crystal surface using PM-IRAS under similar conditions (Pco = 133 mbar, T = 175-750 K). Comparison of the PM-IRAS data for CO adsorption on Pd(111) and Pd nanoclusters indicate that in contrast to the Pd nanoclusters, CO adsorbs molecularly on the Pd(111) surface in a reversible manner, i.e., no dissociation.

引用

页码：4351 / 4357

页数：7

共 42 条

[31] Isocyanate formation in the catalytic reaction of CO + NO on Pd(111): An in situ infrared spectroscopic study at elevated pressures [J].