Understanding Solid-Gas Reaction Mechanisms by Operando Soft X-Ray Absorption Spectroscopy at Ambient Pressure
Ambient-pressure operando soft X-ray absorption spectroscopy (soft-XAS) was applied to study the reactivity of hydroxylated SnO nanoparticles toward reducing gases. H was first used as a test case, showing that the gas phase and surface states can be simultaneously probed: Soft-XAS at the O K-edge g...
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| Vydané v: | Journal of physical chemistry. C Ročník 124; číslo 26; s. 14202 |
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| Hlavní autori: | , , , , , , , , , |
| Médium: | Journal Article |
| Jazyk: | English |
| Vydavateľské údaje: |
United States
02.07.2020
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| ISSN: | 1932-7447 |
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| Shrnutí: | Ambient-pressure operando soft X-ray absorption spectroscopy (soft-XAS) was applied to study the reactivity of hydroxylated SnO
nanoparticles toward reducing gases. H
was first used as a test case, showing that the gas phase and surface states can be simultaneously probed: Soft-XAS at the O K-edge gains sensitivity toward the gas phase, while at the Sn M
-edges, tin surface states are explicitly probed. Results obtained by flowing hydrocarbons (CH
and CH
CHCH
) unequivocally show that these gases react with surface hydroxyl groups to produce water without producing carbon oxides and release electrons that localize on Sn to eventually form SnO. The partially reduced SnO
layer at the surface of SnO
is readily reoxidized to SnO
by treating the sample with O
at mild temperatures (>200 °C), revealing the nature of "electron sponge" of tin oxide. The experiments, combined with DFT calculations, allowed devising of a mechanism for dissociative hydrocarbon adsorption on SnO
, involving direct reduction of Sn sites at the surface via cleavage of C-H bonds and the formation of methoxy- and/or methyl-tin species at the surface. |
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| Bibliografia: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1932-7447 |
| DOI: | 10.1021/acs.jpcc.0c02546 |