X-Ray Absorption and Photoemission Studies of the Active Oxygen for Ethylene Epoxidation over Silver
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
Catalysis Letters
ISSN: 1011-372X
, E-ISSN: 1572-879X
|
| Вых. Данные |
Год: 2001,
Том: 74,
Номер: 3-4,
Страницы: 121-125
Страниц
: 5
DOI:
10.1023/A:1016666021405
|
| Ключевые слова |
Epoxidation, Ethylene, Oxygen, Silver, XANES, XPS |
| Авторы |
Bukhtiyarov V.I.
1
,
Hävecker M.
2
,
Kaichev V.V.
1
,
Knop-Gericke A.
2
,
Mayer R.W.
2
,
Schlögl R.
2
|
| Организации |
| 1 |
Boreskov Institute of Catalysis, Lavrentieva prosp., 5, 630090 Novosibirsk, Russia
|
| 2 |
Fritz-Haber-Institut der MPG, Faradayweg 4-6, D-14195 Berlin (Dahlem), Germany
|
|
Информация о финансировании (2)
|
1
|
Российский фонд фундаментальных исследований
|
00-15-99335
|
|
2
|
Max Planck Society
|
|
Activation of clean polycrystalline silver by a C2H4 + O2 reaction mixture has been studied by XANES, XPS, and UPS. In situ monitoring of the O K-edge XAS spectrum of the pre-treated silver surface revealed a broad signal at 10–20 eV above the threshold. The comparison of the X-ray absorption spectra with O 1s and valence band photoemission data allowed us to attribute this XAS signal to “electrophilic” oxygen (Eb(O 1s) = 530.4 eV) which is known to be active in ethylene epoxidation. The complete absence of XAS features in the photon energy range typical for π* and σ* transitions of molecular oxygen (530–535 eV) indicates both the atomic origin of the electrophilic oxygen and the absence of molecular species on the catalyst surface under the present reaction conditions.