AN XPS STUDY OF METALLIC 3-WAY CATALYSTS - THE EFFECT OF ADDITIVES ON PLATINUM, RHODIUM, AND CERIUM

被引：54

作者：

TALO, A ^{[1
]}

LAHTINEN, J ^{[1
]}

HAUTOJARVI, P ^{[1
]}

机构：

[1] HELSINKI UNIV TECHNOL, PHYS LAB, SF-02150 ESPOO, FINLAND

来源：

APPLIED CATALYSIS B-ENVIRONMENTAL | 1995年 / 5卷 / 03期

关键词：

ALUMINA; CERIA; LANTHANUM; 3-WAY CATALYSTS; PLATINUM; RHODIUM; AGING (THERMAL); X-RAY PHOTOELECTRON SPECTROSCOPY;

D O I：

10.1016/0926-3373(94)00044-1

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 effect of Zr, Si, La, and Pa on the thermal aging of PI, Ph, and Ce in automotive exhaust gas catalysts supported on metal foils was studied with X-ray photoelectron spectroscopy (XPS). Platinum was in metallic state under all circumstances studied in this work. Rhodium was partially (about 30%) oxidized already at room temperature. The decreases in the binding energies of the reduced noble metals due to aging was explained in terms of particle growth. The binding energy of rhodium oxide increased during aging indicating rhodium diffusion into alumina. Cerium was oxidized during aging. It was found that in the lanthanum containing catalysts the binding energies of platinum and rhodium were below the values for bulk metals, and the degree of oxidation of cerium was lower than in the other samples. It was concluded that the presence of lanthanum facilitated the reduction of the noble metals and cerium.

引用

页码：221 / 231

页数：11