Transient Studies on the Role of Oxygen Activation in the Oxidative Coupling of Methane over Sm2O3, Sm2O3/MgO, and MgO Catalytic Surfaces Научная публикация
Журнал |
Journal of Catalysis
ISSN: 0021-9517 , E-ISSN: 1090-2694 |
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Вых. Данные | Год: 1994, Том: 150, Номер: 1, Страницы: 71-80 Страниц : 10 DOI: 10.1006/jcat.1994.1323 | ||||
Ключевые слова | Li/MgO CATALYST; EXCHANGE; OXIDES | ||||
Авторы |
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Организации |
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Информация о финансировании (2)
1 | European Commission | JOUF 0044 |
2 | German Research Foundation |
Реферат:
The interaction of oxygen with catalytic surfaces of MgO, Sm2O3, and Sm2O3 (5 mol%)/MgO and the reaction of methane with short-lived surface oxygen species over Sm2O3 were studied by transient experiments. The oxygen exchange between gas-phase 18O2 surface oxygen 16OS was investigated in the temperature range from 539 to 1035 K. The oxygen-exchange activity decreased from Sm2O3 (Ea = 81 kJ/mol) via Sm2O3/MgO (Ea = 96 kJ/mol) to MgO (Ea = 261 kJ/mol). The presence of methane did not influence the exchange rate of 18O2, with the surface. This indicates (a) that oxygen activation on the surface is faster than activation of methane and (b) that neither gas-phase oxygen nor nondissociated surface oxygen is involved in the reaction with methane under the reaction conditions applied. It was shown that the surface reaction of methane with oxygen intermediates formed from gas-phase O2 is faster than the desorption of any diatomic oxygen species. Over Sm2O3, the degree of oxidative conversion of methane and the resulting product distribution are determined by the amount of surface-oxygen species formed by dissociation of gaseous O2 on the catalyst surface. It is suggested that these active oxygen sites consist of highly reactive short-lived species (below 200 ms) and also species having longer lifetimes.
Библиографическая ссылка:
Buyevskaya O.V.
, Rothaemel M.
, Zanthoff H.W.
, Baerns M.
Transient Studies on the Role of Oxygen Activation in the Oxidative Coupling of Methane over Sm2O3, Sm2O3/MgO, and MgO Catalytic Surfaces
Journal of Catalysis. 1994. V.150. N1. P.71-80. DOI: 10.1006/jcat.1994.1323 WOS Scopus РИНЦ
Transient Studies on the Role of Oxygen Activation in the Oxidative Coupling of Methane over Sm2O3, Sm2O3/MgO, and MgO Catalytic Surfaces
Journal of Catalysis. 1994. V.150. N1. P.71-80. DOI: 10.1006/jcat.1994.1323 WOS Scopus РИНЦ
Даты:
Поступила в редакцию: | 2 февр. 1994 г. |
Принята к публикации: | 10 июн. 1994 г. |
Опубликована в печати: | 1 нояб. 1994 г. |
Опубликована online: | 25 мая 2002 г. |
Идентификаторы БД:
Web of science | WOS:A1994PN46100007 |
Scopus | 2-s2.0-0002438505 |
РИНЦ | 30812829 |
Chemical Abstracts | 1994:680125 |
Chemical Abstracts (print) | 121:280125 |
OpenAlex | W2008830547 |