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 ability of the PTA and MIL101/PTA materials to strongly absorb and condense acetaldehyde vapors was discovered, with the MIL101 /PTA absorbing over 10-fold its dry weight of acetaldehyde condensate at room temperature.
Abstract: Porous materials based on chromium(III) terephthalate metal organic frameworks (MIL-101) and their composites with phosphotungstic acid (PTA) were studied as heterogeneous acid catalysts in aldehyde-alcohol reactions exemplified by acetaldehyde-phenol (A-P) condensation and dimethylacetal formation from benzaldehyde and methanol (B-M reaction). The MIL-101 was synthesized solvothermically in water, and the MIL101/PTA composite materials were obtained by either impregnation of the already prepared MIL-101 porous matrix with phosphotungstic acid solution or by solvothermic treatment of aqueous mixtures of Cr(NO3)3, and terephthalic and phosphotungstic acids. The MIL101/PTA materials appeared to be effective catalysts for both A-P and B-M reactions occurring at room temperature, with half-lives ranging from 0.5 h (A-P) to 1.5–2 h (B-M) and turnover numbers over 600 for A-P and over 2900 for the B-M reaction, respectively. A synergistic effect of the strong acidic moieties (PTA) addition to mildly acidic Bron...
54 citations
TL;DR: In this article, a magnetically separable catalyst consisting of phosphotungstic acid (PTA) supported on imidaz- ole functionalized silica coated cobalt ferrite nanoparticles was prepared.
Abstract: a b s t r a c t A new magnetically separable catalyst consisting of phosphotungstic acid (PTA) supported on imidaz- ole functionalized silica coated cobalt ferrite nanoparticles was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The immobilized phosphotungstic acid was shown to be an efficient heterogeneous catalyst for the synthesis of -aminophosphonates under solvent-free conditions at room temperature. The catalyst is readily recovered by simple magnetic decantation and can be recycled several times with no significant loss of catalytic activity.
54 citations
TL;DR: Sections of phosphotungstic acid stained, araldite embedded liver and acidophil and basophil cells of the anterior pituitary of the mouse were examined in the electron microscope and it was suggested that pores formed by the conjunction of the inner and outer membranes are simple holes in the nuclear membrane.
53 citations
TL;DR: In this article, a family of HPW@UiO-66 catalysts with a stable structure and large specific surface area was used for model oil desulfurization.
53 citations
53 citations