Carbon-13 Nuclear Magnetic Resonance of Simple Molecules Adsorbed on Catalytic Surfaces Научная публикация
| Журнал |
Journal of Physical Chemistry (up to 1996)
ISSN: 0022-3654 |
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| Вых. Данные | Год: 1978, Том: 82, Номер: 15, Страницы: 1752-1760 Страниц : 9 DOI: 10.1021/j100504a019 | ||||||
| Авторы |
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| Организации |
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Информация о финансировании (1)
| 1 | National Science Foundation |
Реферат:
Carbon-13 nuclear magnetic resonance studies were carried out on methane, carbon monoxide, acetylene, ethylene,
propylene, methylacetylene, carbonyl sulfide, cyclopropane, propane, and isobutane on Na-A, Na-X, Na-Y, H-Y, Ag-Y, decationated Y zeolites, silica, and dissolved in DCC13. When iron impurities were minimized sharp lines (about 10 Hz wide) were obtained permitting determination of the chemical shift to a precision of 0.05 ppm and the hydrogen-carbon coupling constant to an accuracy of 0.2 Hz. All chemical shifts were referred to the gaseous state and the bulk magnetic susceptibility correction was obtained by measuring the shift of nonadsorbing methane. The chemical shifts are of comparable magnitude in solution as on adsorption. The shift is interpreted to be due to strong electric fields of 0.1-0.5 V Á"1 on the surface of the adsorbents. This field causes either a change in the separation to excited states of the adsorbed molecule, or a transfer of electrons to and from the molecule and the surface, or a redistribution of electrons within the molecule. The coupling constants permit differentiation between these mechanisms and also a determination of the increase or decrease of individual carbon-hydrogen distances. The temperature dependence of the width of the lines permits determination of the energy requirement for the mobility of adsorbed species. The relaxation time measurements give further information on the mobility of the molecules and of their segments in the adsorbed phase. A new mechanism of catalysis is proposed involving a change by the electric field of the catalyst in the distance of the excited, more reactive, electronic state of the adsorbed molecule.
Библиографическая ссылка:
Denney D.
, Mastikhin V.M.
, Namba S.
, Turkevich J.
Carbon-13 Nuclear Magnetic Resonance of Simple Molecules Adsorbed on Catalytic Surfaces
Journal of Physical Chemistry (up to 1996). 1978. V.82. N15. P.1752-1760. DOI: 10.1021/j100504a019 WOS Scopus РИНЦ CAPlusCA OpenAlex
Carbon-13 Nuclear Magnetic Resonance of Simple Molecules Adsorbed on Catalytic Surfaces
Journal of Physical Chemistry (up to 1996). 1978. V.82. N15. P.1752-1760. DOI: 10.1021/j100504a019 WOS Scopus РИНЦ CAPlusCA OpenAlex
Даты:
| Поступила в редакцию: | 12 дек. 1977 г. |
| Принята к публикации: | 5 мая 1978 г. |
| Опубликована в печати: | 1 июл. 1978 г. |
| Опубликована online: | 1 мая 2002 г. |
Идентификаторы БД:
| Web of science: | WOS:A1978FH80600019 |
| Scopus: | 2-s2.0-0011302092 |
| РИНЦ: | 47293350 |
| Chemical Abstracts: | 1978:480581 |
| Chemical Abstracts (print): | 89:80581 |
| OpenAlex: | W2037256382 |