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: In this article, PTA/AC catalysts with various AC sizes or PTA content have been synthesized and characterized by N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy and temperature programmed desorption of ammonia.
Abstract: Phosphotungstic acid/activated carbon (PTA/AC) catalysts with various AC sizes or PTA content have been synthesized and characterized by N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy and temperature programmed desorption of ammonia. These catalysts were then evaluated in terms of the removal of dibenzothiophene (DBT) by ultrasoundassisted oxidative desulfurization process. The results showed that the DBT conversion obviously increased with the decrease of AC support size and the increase of PTA content. After supporting PTA on AC, the DBT conversion can be improved by 38.9% after ultrasound irradiation for 10 min. In addition, the stability tests of PTA/AC showed that the catalytic oxidative activity of PTA/AC was nearly kept constant after ultrasound irradiation for 20 min, which makes it a promising catalyst to use in ultrasound-assisted oxidative desulfurization process.
13 citations
TL;DR: Results are considered to cast further doubt upon the reliability of phosphotungstic acid/chromic acid (PTAC) and STAC as specific stains for plant plasma membranes, while demonstrating the usefulness of LaCl3 as a possible plasma membrane stain for isolated protoplasts.
13 citations
TL;DR: The water-soluble chitosan with a viscosity-average molecular weight (M(v)) of 4900 was obtained under the optimum degradation conditions and was characterized by FTIR, ultraviolet-visible diffuse reflection spectra (UV-vis DRS), and X-ray powder diffraction analysis.
13 citations
TL;DR: In this article, the properties of the heteropolytungstic acids are described, and simple demonstrations of three new photographic processes based upon phosphotungstic acid are outlined, which include a printing out process producing images in pigments of basic dyes; phototropic and therefore reusable, printing out materials; and the development of a latent image.
Abstract: The heteropolytungstic acids, especially certain of the phosphotungstic and silicotungstic acids, are photooxidizing agents with properties that suggest their use in photographic processes. The chemical and physical properties of the substances are described, and simple demonstrations of three new photographic processes based upon phosphotungstic acid are outlined. These comprise a printing out process producing images in pigments of basic dyes; phototropic, and therefore reusable, printing out materials; and the development of a latent image.
13 citations
TL;DR: In this article, a series of tungsten oxide supported on commercial ZrO 2 was synthesized via a traditional impregnation method using ammonium tungstate, phosphotungstic acid hydrate and tungstane acid-oxalic acid complex as the tungstein precursors.
Abstract: A series of tungsten oxide supported on commercial ZrO 2 was synthesized via a traditional impregnation method using ammonium tungstate, phosphotungstic acid hydrate and tungstic acid–oxalic acid complex as the tungsten precursors. The supported catalysts were characterized by XRD, UV–vis DRS, Raman and XPS. It was found that the tungsten precursor and the calcination temperature were crucial to the dispersion and the nature of the tungsten species on ZrO 2 . The catalytic performances of the catalysts were investigated in the oxidative lactonization of 1,2-benzenedimethanol to phthalide with H 2 O 2 . The excellent catalytic performance of the catalyst prepared by calcination at 823 K after using tungstic acid-oxalic acid complex as the tungsten precursor was attributed to the presence of polymeric WO 6 units.
13 citations