TPD and XPS investigation of the interaction of SO2 with model ceria catalysts

被引：105

作者：

Ferriz, RM ^{[1
]}

Gorte, RJ ^{[1
]}

Vohs, JM ^{[1
]}

机构：

[1] Univ Penn, Dept Chem Engn, Philadelphia, PA 19104 USA

来源：

CATALYSIS LETTERS | 2002年 / 82卷 / 1-2期

基金：

美国能源部;

关键词：

ceria; SO2; cerium sulfate; TPD; XPS;

D O I：

10.1023/A:1020512713021

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：

The interaction of SO2 with model thin-film ceria catalysts was studied using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). During TPD of ceria samples that had been exposed to SO2 at room temperature, SO2 desorbed in peaks centered at 473, 883 and 963 K. The lower temperature peak is associated with molecularly adsorbed SO2, while the higher temperature peaks are due to decomposition of adsorbed sulfates. XPS results show that at room temperature a small fraction of the adsorbed SO2 is oxidized to SO42- using oxygen supplied by the ceria. This reaction also results in partial reduction of the ceria surface. High coverages of surface sulfate species could be produced by exposing the ceria samples to mixtures of SO2 and O-2 at 573 K. In addition to producing gaseous SO2, thermal decomposition of surface sulfates at temperatures above 823 K resulted in the formation of an oxy-sulfide (Ce2O2S) on the ceria surface.

引用

页码：123 / 129

页数：7

共 29 条

[1] Axial characterization of oxygen storage capacity in close-coupled lightoff and underfloor catalytic converters and impact of sulfur [J].