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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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Journal ArticleDOI
TL;DR: In this paper, a novel catalytic membrane has been prepared by linking phosphotungstic acid H3PW12O40 (W12), a polyoxometalate having interesting properties as photocatalyst, on the surface of plasma-modified membranes.
Abstract: Novel catalytic membranes have been prepared by linking phosphotungstic acid H3PW12O40 (W12), a polyoxometalate having interesting properties as photocatalyst, on the surface of plasma-modified membranes. Porous flat-sheet membranes made of polyvinylidene fluoride (PVDF) have been prepared by a phase-inversion technique induced by a nonsolvent. These membranes have been modified by plasma treatments on the surface to graft N-containing polar groups that are able to act as binding sites with W12 (PVDF−NH2−W12). A comparison of the surface and bulk properties of the native and modified PVDF membranes has been reported. Catalytic activity of the PVDF−NH2−W12 membranes has been evaluated in the aerobic degradation reaction of phenol in water. Catalytic tests have been carried out in a membrane reactor operating in continuous mode. Better catalytic performances have been observed for the W12 heterogenized on PVDF membrane than for W12 in a homogeneous phase. Moreover, PVDF−NH2−W12 membranes have given proof of...

58 citations

Journal ArticleDOI
TL;DR: In this article, the influence of the catalyst on the selectivity for acylation and alkylation with crotonic acid has been studied, and it was shown that all the catalysts are more active for acylation than for alkylation.
Abstract: Pure phosphotungstic acid (H 3 PW 12 O 40 ), supported on SiO 2 and in the form of Cesium salts have been studied as acid catalysts for the acylation of toluene, p -xylene and m -xylene with crotonic acid. Since crotonic acid can either alkylate and/or acylate the alkylaromatic compounds, it was specifically selected to study the influence of the catalyst on the selectivity for these two competing reactions. Analysis of products obtained when acylating with an α , β -unsaturated acid show that all the catalysts are more active for acylation than for alkylation. Heteropolyacids were found to be more active than zeolites H-Y and Beta, even when the activity per acid site was considered. In the case of heteropolyacids, their activity is directly related to the number of accessible Bronsted acid sites.

58 citations

Journal ArticleDOI
TL;DR: In this paper, a polyoxometalate-based sulfonated ionic liquid catalysts were used for esterification reactions of palmitic acid to biodiesel.

58 citations

Journal ArticleDOI
Jun Cheng1, Hao Guo1, Xiao Yang1, Yuxiang Mao1, Lei Qian1, Yanxia Zhu1, Weijuan Yang1 
TL;DR: In this paper, a bifunctional heterogeneous catalyst was synthesized by modifying ZIF-67 with phosphotungstic acid (HPW) for biodiesel production.

58 citations

Journal ArticleDOI
TL;DR: Statements in the literature assuming that phosphotungstic acid (PTA) is a stain for polysaccharide require correction.
Abstract: Statements in the literature assuming that phosphotungstic acid (PTA) is a stain for polysaccharide require correction. Most quioted is a publication of Pease (J. Ultrastruct. Res. 15: 555. 1966), the first paragraph of which has the following statement referring to tissues prepared for electron microscopy by displacement of water by glycol, embedment in hydroxypropyl methacrylate and eventual PTA staining: “Goblet cell mucus,

58 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202352
2022121
2021102
2020102
2019115
2018126