Discerning the Metal Doping Effect on Surface Redox and Acidic Properties in a MoVTeNbOx for Propa(e)ne Oxidation
Adding a small quantity of K or Bi to a MoVTeNbO x via impregnation with inorganic solutions modifies its surface acid and redox properties and its catalytic performance in propa(e)ne partial oxidation to acrylic acid (AA) without detriment to its pristine crystalline structure. Bi-doping encourages...
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Veröffentlicht in: | ACS omega 2021-06, Vol.6 (23), p.15279-15291 |
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Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Adding a small quantity
of K or Bi to a MoVTeNbO
x
via impregnation
with inorganic solutions modifies its
surface acid and redox properties and its catalytic performance in
propa(e)ne partial oxidation to acrylic acid (AA) without detriment
to its pristine crystalline structure. Bi-doping encourages propane
oxydehydrogenation to propene, thus enlarging the net production rate
of AA up to 35% more. The easier propane activation/higher AA production
over the Bi-doped catalyst is ascribed to its higher content of surface
V leading to a larger amount of total V
5+
species, the
isolation site effect of NbO
x
species
on V, and its higher Lewis acidity. K-doping does not affect propane
oxydehydrogenation to propene but mainly acts over propene once formed,
also increasing AA to a similar extent as Bi-doping. Although K-doping
lowers propene conversion, it is converted more selectively to acrylic
acid owing to its reduced Brønsted acidity and the presence of
more Mo
6+
species, thereby favoring propene transformation
via the π-allylic species route producing acrylic acid over
that forming acetic acid and CO
x
via acetone
oxidation and that yielding directly CO
x
. |
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ISSN: | 2470-1343 |
DOI: | 10.1021/acsomega.1c01591 |