FT-IR Spectroscopic Studies of Hydrocarbon Trapping in Ag+-ZSM-5 for Gasoline Engines under Cold-Start Conditions
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
Applied Catalysis B: Environmental
ISSN: 0926-3373
, E-ISSN: 1873-3883
|
| Вых. Данные |
Год: 2001,
Том: 35,
Номер: 2,
Страницы: 125-136
Страниц
: 12
DOI:
10.1016/S0926-3373(01)00247-8
|
| Ключевые слова |
Ag-ZSM-5, Cold-start, FT-IR, Hydrocarbon trap, Propylene, Toluene |
| Авторы |
Liu Xinsheng
,
Lampert Jordan K.
,
Arendarskii Dmitrii A.
,
Farrauto Robert J.
|
| Организации |
|
A detailed study of adsorption of automobile exhaust hydrocarbons in Ag+-exchanged zeolites under cold-start conditions (room temperature and in the presence of water) was carried out with FT-IR spectroscopy, using toluene and propylene as probes. The results show that exchanged Ag+ in zeolites is unique for trapping olefin and aromatic hydrocarbons due to its resistance to water adsorption. In contrast, exchanged Cu2+ in zeolites, which has good hydrocarbon trapping properties under dry conditions, does not trap hydrocarbons under wet conditions. Here, solvation of Cu2+ screens the interactions of the cation with adsorbed hydrocarbons. The results also show that, in addition to the nature of the cation, the structure of the zeolite also plays a role in hydrocarbon trapping. Aging at high temperatures, with water vapor (∼10%) and SO2 (∼15 ppm), leads to a decrease of the trapping centers in the zeolites due to framework dealumination.