The role of niobia location on the acidic and catalytic functionalities of heteropoly tungstate

[Display omitted] 12-Tungstophosphoric acid (TPA) was modified systematically by incorporating niobium into its primary and secondary structure. TPA supported on niobia catalyst was also prepared by impregnation method. These catalysts were characterized by FT-infra red, X-ray diffraction, Laser Ram...

Full description

Saved in:
Bibliographic Details
Published inApplied catalysis. A, General Vol. 502; pp. 297 - 304
Main Authors Ramesh Kumar, Ch, Gatla, S., Mathon, O., Pascarelli, S., Lingaiah, N.
Format Journal Article
LanguageEnglish
Published Elsevier B.V 05.08.2015
Subjects
Anisole
Benzyl alcohol
Dibenzylether
Heteropoly tungstate
Keggin ion
Niobium
Benzyl alcohol
Dibenzylether
Heteropoly tungstate
Anisole
Keggin ion
Niobium
Online AccessGet full text

Cover

More Information
Summary:[Display omitted] 12-Tungstophosphoric acid (TPA) was modified systematically by incorporating niobium into its primary and secondary structure. TPA supported on niobia catalyst was also prepared by impregnation method. These catalysts were characterized by FT-infra red, X-ray diffraction, Laser Raman, X-ray photo electron spectroscopy, X-ray absorption spectroscopy, UV–vis diffuse reflectance spectroscopy, solid state 31P nuclear magnetic resonance spectroscopy, temperature programmed desorption of ammonia and pyridine adsorbed FT-IR spectroscopy. Characterization results suggest the presence of intact Keggin structure after modification of parent TPA. Incorporation of Nb into the secondary structure results in generation of Lewis acidic sites. Nb containing TPA catalysts exhibited high acidity compared to the TPA supported on niobia catalyst. The activity of the catalysts was evaluated for benzylation of anisole with benzyl alcohol. Catalyst activity depended on the location of niobium ion in the heteropoly tungstate.
ISSN:0926-860X
1873-3875
DOI:10.1016/j.apcata.2015.06.023