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 paper, the preparation of partial acetylation of cellulose derived from rice straw was catalyzed by phosphotungstic acid with various numbers of crystal water, and H3PW12O40·4H2O was found to be as effective catalyst.
Abstract: The preparation of partial acetylation of cellulose derived from rice straw was catalyzed by phosphotungstic acid with various numbers of crystal water, and H3PW12O40·4H2O was found to be as effective catalyst. The yield of the cellulose acetate was significantly enhanced by converting cellulose directly isolated from rice straw into microcrystalline cellulose before acetylation. The optimization of the acetylation was investigated by varying the amount of catalyst and acetic anhydride as well as reaction conditions including reaction time and medium, and a degree of substitution (DS) value of 2.29 and yield of 62.9% were obtained under the optimized conditions. The structure and the formation of the acetylated product were confirmed by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD) technique, the thermal properties were determined by thermal analysis including thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC), and the morphology was observed by scanning electron microscope (SEM). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41212.
13 citations
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TL;DR: In this article, the nitrogen fraction from cheese, soluble in phosphotungstic acid has been analyzed by gel permeation and high performance liquid chromatography, showing that there are no peptides of molecular weight higher than 700 daltons.
Abstract: The nitrogen fraction from cheese, soluble in phosphotungstic acid has been analyzed by gel permeation and high performance liquid chromatography. Elution profiles of this fraction on Sephadex G-10 show that there are no peptides of molecular weight higher than 700 daltons. Six fractions have been obtained. The first one has the peptides and some amino acids. Fractions II to VI contains mostly free amino acids. Fraction I has been separated into many peaks by HPLC. Six or seven of these peaks are presumed to correspond to peptides.
13 citations
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TL;DR: In this article , a comparative study of 1,2-dichloroethane (1, 2-DCE) and toluene oxidation over the Ru/TiO2, phosphotungstic acid (HPW)-modified Ru/ TiO2 and oxygen vacancy-rich Ru/OOx catalysts was conducted.
Abstract: The compositions of volatile organic compounds (VOCs) under actual industrial conditions are often complex; especially, the interaction of intermediate products easily leads to more toxic emissions that are harmful to the atmospheric environment and human health. Herein, we report a comparative investigation on 1,2-dichloroethane (1,2-DCE) and (1,2-DCE + toluene) oxidation over the Ru/TiO2, phosphotungstic acid (HPW)-modified Ru/TiO2, and oxygen vacancy-rich Ru/TiOx catalysts. The doping of HPW successfully introduced the 1,2-DCE adsorption sites to promote its oxidation and exhibited outstanding water resistance. For the mixed VOCs, Ru/HPW-TiO2 promoted the preferential and superfluous adsorption of toluene and resulted in the inhibition of 1,2-DCE degradation. Therefore, HPW modification is a successful strategy in catalytic 1,2-DCE oxidation, but Brønsted acid sites tend to adsorb toluene in the mixed VOC oxidation. The Ru/TiOx catalyst exhibited excellent activity and stability in the oxidation of mixed VOCs and could inhibit the generation of byproducts and Cl2 compared with the Ru/HPW-TiO2 catalyst. Compared with the Brønsted acid modification, the oxygen vacancy-rich catalysts are significantly suitable for the oxidation of multicomponent VOCs.
13 citations
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TL;DR: In this article, a facile fabrication of polydiphenylamine/phosphotungstic acid/platinum (PDPA/PTA/Pt) nanocomposites modified electrode via electrodeposition method for efficient electro-oxidation of methanol in acidic medium was demonstrated.
13 citations
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TL;DR: In this article, the SPAE/GO/PWA composite membrane comprising 0.7 wt% graphene oxide (GO) and 36 Wt% phosphotungstic acid (PWA) was integrated into sulfonated poly(arylene ether) (SPAE) through a solution casting approach to create a potential composite membrane for PEMFC applications.
Abstract: The development of potential and novel proton exchange membranes (PEMs) is imperative for the further commercialization of PEM fuel cells (PEMFCs). In this work, phosphotungstic acid (PWA) and graphene oxide (GO) were integrated into sulfonated poly(arylene ether) (SPAE) through a solution casting approach to create a potential composite membrane for PEMFC applications. Thermal stability of membranes was observed using thermogravimetric analysis (TGA), and the SPAE/GO/PWA membranes exhibited high thermal stability compared to pristine SPAE membranes, owing to the interaction between SPAEK, GO, and PWA. By using a scanning electron microscope (SEM) and atomic force microscope (AFM), we observed that GO and PWA were evenly distributed throughout the SPAE matrix. The SPAE/GO/PWA composite membrane comprising 0.7 wt% GO and 36 wt% PWA exhibited a maximum proton conductivity of 186.3 mS cm-1 at 90 °C under 100% relative humidity (RH). As a result, SPAE/GO/PWA composite membrane exhibited 193.3 mW cm-2 of the maximum power density at 70 °C under 100% RH in PEMFCs.
13 citations