Influence of cesium and vanadium contents on the oxidation functionalities of heteropoly molybdate catalysts

Rao, P.S.N.; Parameswaram, G.; Rao, Anand V.; Lingaiah, N.

doi:10.1016/j.molcata.2015.01.023

Cited by 18 publications

(16 citation statements)

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“…[10][11][12][13] The most extensively studied catalysts involve Mo/V/Ce based oxides. [14][15][16][17][18][19] Much research has been done into molybdenum oxide catalysts supported on different metal oxides. [20][21][22][23][24] Catalytic performance of the molybdena catalysts depends on the specic support, promoters, molybdena loading, calcination temperature, etc.…”

Section: Introductionmentioning

confidence: 99%

The stability and catalytic performance of K-modified molybdena supported on a titanate nanostructured catalyst in the oxidative dehydrogenation of propane

et al. 2019

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Section: Introductionmentioning

confidence: 99%

The stability and catalytic performance of K-modified molybdena supported on a titanate nanostructured catalyst in the oxidative dehydrogenation of propane

et al. 2019

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“…There are several examples of vanadium‐substituted POM catalysts promoting highly selective, quantitative reactions; however, current issues associated with POM‐mediated oxidation protocols include high reaction temperatures (~90 – 135 °C), high catalyst loadings ( e.g . ~40 mol‐%), and some examples require co‐catalysts for optimal performance . These considerations somewhat reduce the overall synthetic utility of the resulting methods.…”

Section: Introductionmentioning

confidence: 99%

Alcohol Oxidations Using Reduced Polyoxovanadates

Campbell

Sulejmanovic

Schiller

et al. 2017

Helvetica Chimica Acta

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A full account of our recently communicated room temperature alcohol oxidation using reduced polyoxovanadates (r‐POVs) is presented. Extensive optimizations revealed optimal conditions employing 0.02 equiv. of r‐POV catalyst Cs5(V14As8O42Cl), 5 equiv. tert‐butyl hydrogen peroxide (tBuOOH) as the terminal co‐oxidant, in an acetone solvent for the quantitative oxidation of aryl‐substituted secondary alcohols to their ketone products. The substrate scope tolerates most aryl substituted secondary alcohols in good to quantitative yields while alkyl secondary and primary activated alcohols were sluggish in comparison under similar conditions. Catalyst recyclability was successful on a 1.0 mmol scale of starting alcohol 1‐phenylethanol. The oxidation was also successfully promoted by the VIV/VV mixed valent polyoxovanadate (POV) Cs11Na3Cl5(V15O36Cl). Finally, a third POV, Cs2.64(V5O9)(AsO4)2, was investigated for catalytic activity using our established reaction protocol, but proved ineffective as compared to the other two r‐POV catalysts. This study expands the field of POM‐mediated alcohol oxidations to include underexplored r‐POV catalysts. While our catalysts do not supplant the best catalysts known for the transformation, their study may inform the development of other novel oxidative transformations mediated by r‐POVs.

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“…Besides the potential reduction, acid properties can be useful to explain the behavior of the Vanadium-doped phosphomolybdic acids in oxidations reactions of geraniol, Like Weinstock et al reported, Keggin-type (Mo-V-P) HAPs possess strong Brønsted acidity, which is beneficial to the oxidative catalytic transformations of biomass derived (WEINSTOCK; SCHREIBER; NEUMANN, 2018). In effect, previous research has described that the formation of the peroxo-metal intermediated between the peroxide and the HAP catalyst (i.e., V, Mo or W HPA) is bountied with the Vanadium atom presence (CASARINI et al, 1993;RAO et al, 2015;PALERMO et al, 2016;PALERMO et al, 2015).…”

Section: Effect Of Vanadium Doping On the Conversion And Selectivity ...mentioning

confidence: 99%

“…This geraniol aldehyde is obtained by decomposition of peroxide geraniol intermediated . Previous research describes that this composition to a carbonylic compound (geraniol aldehyde) is more favourable when the catalyst is easily oxidable, it means, through a fast interconversion of one electron (i.e., V +4 /V +5 ), which in this case is promoted by high Vanadium load (RAO et al, 2015)(PALERMO et al, 2016PALERMO et al, 2015;PILLAI;SAHLE-DEMESSIE, 2004). Same results were observed when Sodium salt of this acid (i.e., Na6PMo9V3O40)…”

Section: Effect Of Vanadium Doping On the Conversion And Selectivity ...mentioning

confidence: 99%

Synthesis and evaluation of Niobium or Vanadium – doped heteropolyacid catalysts in oxidation and acetalization reactions of alcohols and aldehydes derivated of biomass

Torres¹

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Aldehydes derived from biomass and terpene alcohols are abundant raw materials, of plant origin, and of interest for production of fine chemicals products, such as fragrances, pharmaceuticals and agrochemicals. Recently, for economic and environmental reasons, catalytic processes have been developed to transform these renewable resources into chemical products with higher added value. In this work, heteropolyacids (HAPs) obtained from phosphomolybdic acid doped with 1, 2, and 3 mol of Niobium (i.e., H 4 PMo 11 Nb 1 O 40 , H 5 PMo 10 Nb 2 O 40 and H 6 PMo 9 Nb 3 O 40 ) were synthesized and evaluated as catalysts in oxidation and acetalization reactions of aldehydes present in the biomass. Niobium- doped HAPs were synthesized from different precursors: MoO 3 , Nb 2 O 5 , H 3 PO 4. Furthermore, HAPs obtained from the doping of phosphomolybdic acid with Vanadium were applied in oxidation reactions of terpene alcohols by hydrogen peroxide in acetonitrile solutions. The synthesis procedures used proved to be efficient, since the catalyst were obtained with satisfactory yields. All synthesized acids were characterized by infrared spectroscopy analysis, ultraviolet-visible spectroscopy, thermal analysis, surface area and porosimetry, X-ray diffraction, and potentiometric titration. The catalytic activity of HAPs was evaluated in different oxidation and acetalization reactions. The Nb-doped HAPs were evaluated in oxidative esterification reaction of furfural, chosen as a model substrate due to its reactivity and industrial interest. In addition, they were also evaluated in acetalization reaction. In this reaction, the amount of Nb does not seem to have produced a significant difference in terms of conversion and selectivity. Furthermore, most of the catalytic tests were performed with H 6 PMo 9 Nb 3 O 40 obtaining conversion of approximately 50% and 2-furfuraldehyde-methylacetal as the only product. The concentration of 0.0312 mol % of catalyst presents the best catalytic activity. Finally, the reaction was extended to benzaldehyde, obtaining similar results. Tests performed with Vanadium-doped catalysts showed that H 4 PMo 11 VO 40 was the most active and selective in the oxidation of geraniol (the substrate chosen as model terpene alcohol) toward geraldehyde, mono and diepoxide, with epoxide being the major product. Conversion greater than 94% was obtained with selectivity between 80 and 85% for epoxide geraniol. H 4 PMo 11 VO 40 has also been tested in the oxidation of other terpene alcohols, and has been shown to be active in the oxidation of nerol. Keywords: Furfural. Terpene alcohols. Keggin Heteropolyacids. Oxidative esterification

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Influence of cesium and vanadium contents on the oxidation functionalities of heteropoly molybdate catalysts

Cited by 18 publications

References 43 publications

The stability and catalytic performance of K-modified molybdena supported on a titanate nanostructured catalyst in the oxidative dehydrogenation of propane

The stability and catalytic performance of K-modified molybdena supported on a titanate nanostructured catalyst in the oxidative dehydrogenation of propane

Alcohol Oxidations Using Reduced Polyoxovanadates

Synthesis and evaluation of Niobium or Vanadium – doped heteropolyacid catalysts in oxidation and acetalization reactions of alcohols and aldehydes derivated of biomass

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