The Nature of Electrophilic and Nucleophilic Oxygen Adsorbed on Silver
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Переводная
|
| Конференция |
Механизмы каталитических реакций: VI российская конф. (с междунар. участием)
01-05 окт. 2002
,
Москва
|
| Журнал |
Kinetics and Catalysis
ISSN: 0023-1584
, E-ISSN: 1608-3210
|
| Вых. Данные |
Год: 2003,
Том: 44,
Номер: 3,
Страницы: 432-440
Страниц
: 9
DOI:
10.1023/A:1024459305551
|
| Авторы |
Kaichev V.V.
1
,
Bukhtiyarov V.I.
1
,
Hävecker M.
2
,
Knop-Gericke A.
2
,
Mayer R.W.
2
,
Schlögl R.
2
|
| Организации |
| 1 |
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, Novosibirsk, 630090 Russia
|
| 2 |
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
|
|
Информация о финансировании (1)
|
1
|
Российский фонд фундаментальных исследований
|
00-15-99335
|
Results of a spectroscopic study of two forms of adsorbed atomic oxygen on a silver surface, which participate in ethylene epoxidation reaction, are presented. The possibility of the combined use of the methods of photoelectron spectroscopy and X-ray absorption for a detailed analysis of adsorbate electron structure on solid surfaces is demonstrated. It is found that a significant difference in the position of O 1s lines for nucleophilic (528.3 eV) and electrophilic (530.4 eV) oxygen is determined by the effects of the initial state, that is, by the difference in the charge state of oxygen anions. The use of the well-know correlation of the Auger line splitting with a Pauling charge at an oxygen atom showed a substantial difference (∼1 electron charge unit) in charge transfer from metal to the nucleophilic or electrophilic adsorbed oxygen atom. Based on the X-ray absorption data of the oxygen K-edge, it is found that there is a substantial overlap of the 4d- and 5sp orbitals of silver with oxygen 2p orbitals in the nucleophilic state in the formation of an Ag–O bond and there is only an overlap of 5sp orbitals of silver with oxygen 2p orbitals in the electrophilic state. Structural models of the adsorption site are presented for both states. The conclusion is drawn that the charge state of oxygen in oxide systems may depend substantially on its binding to metal atoms.