A study of the deactivation by sulfur and regeneration of a model NSR Pt/Ba/Al2O3 catalyst

被引：60

作者：

Elbouazzaoui, S ^{[1
]}

Corbos, EC ^{[1
]}

Courtois, X ^{[1
]}

Marecot, P ^{[1
]}

Duprez, D ^{[1
]}

机构：

[1] LACCO, UMR 6503, F-86022 Poitiers, France

来源：

APPLIED CATALYSIS B-ENVIRONMENTAL | 2005年 / 61卷 / 3-4期

关键词：

sulfur; deactivation; thermal treatment; barium; NSR catalyst;

D O I：

10.1016/j.apcatb.2005.05.012

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 deactivation by sulfur and regeneration of a model Pt/Ba/Al2O3 NO, trap catalyst is studied by hydrogen temperature programmed reduction (TPR), X-ray diffraction (XRD), and NO, storage capacity measurements. The TPR profile of the sulfated catalyst in lean conditions at 400 degrees C reveals three main peaks corresponding to aluminum sulfates (similar to 550 degrees C), "surface" barium sulfates (similar to 650 degrees C) and "bulk" barium sulfates (similar to 750 degrees C). Platinum plays a role in the reduction of the two former types of sulfates while the reduction of "bulk" barium sulfates is not influenced by the metallic phase. The thermal treatment of the sulfated catalyst in oxidizing conditions until 800 degrees C leads to a stabilization of sulfates which become less reducible. Stable barium sulfides are formed during the regeneration under hydrogen at 800 degrees C. However, the presence of carbon dioxide and water in the rich mixture allows eliminating more or less sulfides and sulfates, depending on the temperature and time. The regeneration in the former mixture at 650 degrees C leads to the total recovery of the NOx storage capacity even if "bulk" barium sulfates are still present on the catalyst. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：236 / 243

页数：8

共 22 条

[1] Sulfur deactivation of NOx storage catalysts:: influence of exposure conditions and noble metal [J].