We have studied platinum catalysts supported on silicon nitride Si 3N4 in the process of deep oxidation of methane. We have used transmission electron microscopy and X-ray photoelectron spectroscopy to study the surface properties of the Pt/Si3N4 samples before and after the catalytic reaction. We have established that the metallic platinum particles in freshly prepared systems are characterized by average sizes of 1.7-5.3 nm, while after the catalytic reaction we observe formation of Pt crystallites up to 30-70 nm in size. We hypothesize that the observed deactivation of platinum catalysts in deep oxidation of methane is connected with crystallization of the metallic particles and their entrainment with the reaction products during catalysis.
|Страницы (с... по...)||241-245|
|Журнал||Theoretical and Experimental Chemistry|
|Статус публикации||Опубликовано - июл 2004|
ASJC Scopus subject areas