Topic
Phosphotungstic acid
About: Phosphotungstic acid is a research topic. Over the lifetime, 1925 publications have been published within this topic receiving 38059 citations. The topic is also known as: Phosphowolframic acid.
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TL;DR: The UV-photon-induced degradation of heptafluorobutanoic acid was investigated in acidic aqueous solutions in the presence of titanium dioxide and the formation rate of CO(2) increased with illumination time, while both perfluorinated sulfonic acids are persistent under the experimental conditions employed in this study.
121 citations
TL;DR: Geboers et al. as mentioned in this paper evaluated the potential of the insoluble non-stoichiometric caesium salts of HPAs, viz. CsPW and CsSiW, in combination with Ru on carbon (Ru/C) for the conversion of cellulose.
117 citations
TL;DR: A simplified extraction and catalytic oxidative desulfurization (ECODS) system composed of phosphotungstic acid (H3PW12O40·14H2O), 30% H2O2, and [bmim]BF4 was found suitable for the deep removal of sulfur in model oil as mentioned in this paper.
Abstract: A simplified extraction and catalytic oxidative desulfurization (ECODS) system composed of phosphotungstic acid (H3PW12O40·14H2O), 30% H2O2, and [bmim]BF4 was found suitable for the deep removal of sulfur in model oil. By this desulfurization system dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT) could be effectively removed. Removal of DBT could reach 98.2% at room temperature (30 °C) for 1 h, which was remarkably superior to mere solvent extraction with IL (14.2%) or catalytic oxidation without IL (15.9%). When the reaction temperature increased to 70 °C, treatment of BT, DBT, and 4,6-DMDBT with our ECODS system showed 100% removal of sulfur compounds in 3 h. This desulfurization system could be recycled five times with slight decrease in activity.
117 citations
TL;DR: In this paper, the effects of the polar solvent on the hydrothermal stability have been comprehensively studied by washing the samples with an EtOH/H2O mixture and conducting esterification involving polar solvents.
Abstract: Phosphotungstic acid (HPWA) has been introduced into the mesoporous molecule sieve SBA-15 by a sol–gel technique. The samples were characterized by XRD, BET, FT-IR, XRF and NH3-TPD. The effects of the polar solvent on the hydrothermal stability have been comprehensively studied by washing the samples with an EtOH/H2O mixture and conducting esterification involving polar solvents. Although the acid amount of the fresh impregnated catalyst was superior to the sol–gel counterpart, the sol–gel derived composite is more stable in the acidic property and the structural regularity of the mesoporous material than the impregnated sample. Catalysis tests including reusability of the samples also prove that the sol–gel derived composite is more suitable for the use for heterogeneous catalysis. © 2004 Elsevier B.V. All rights reserved.
116 citations
TL;DR: In this paper, a series of phosphotungstic acid/mesoporous graphitic carbon nitride (mpg-C3N4) catalysts were successfully prepared by immobilizing HPW (H3PW12O40, HPW) on mesoporous carbon carbon dioxide.
Abstract: The phosphotungstic acid/mesoporous graphitic carbon nitride catalyst was successfully prepared by immobilizing phosphotungstic acid (H3PW12O40, HPW) on mesoporous graphitic carbon nitride (mpg-C3N4). The prepared series of HPW/mpg-C3N4 catalysts was characterized via X-ray diffraction, nitrogen adsorption–desorption isotherm, Fourier transform infrared spectroscopy, transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, and thermogravimetric analysis. Results showed that the Keggin structure of HPW active species is still kept after being immobilized on the mpg-C3N4 surface. The HPW/mpg-C3N4 catalyst showed a high catalytic activity in the oxidative desulfurization process. Dibenzothiophene can be removed completely under optimal reaction conditions, and no significant decrease in the catalytic activity of the catalyst was observed after 15 recycles.
115 citations