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Synthesis and characterization of a novel tungstosilicic acid immobilized on zeolites catalyst for the photodegradation of methyl orange
(Elsevier Science, 2016-07)
Materials based on tungstosilicic acid (TSA) immobilized on zeolites (NH4Y and NH4ZSM5) were prepared by wet impregnation of the zeolite matrix with TSA aqueous solutions. The concentration was varied in order to obtain ...
Properties of mesoporous tungstosilicic acid/titania composites prepared by sol-gel method
(Elsevier Science, 2010-03-15)
The tungstosilicic acid/titania composites were prepared by the sol–gel method. Titanium isopropoxide was used as titania precursor, and urea as a low-cost template. The tungstosilicic acid (TSA) was added in the same step ...
A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
(Elsevier Science, 2007-06)
Nonstoichiometric cesium and rubidium salts of tungstosilicic acid (TSA) were synthesized by precipitation. These solids are insoluble in water, due to the low solvation energy of large cations, have high specific surface ...
Visible-light-absorbing mesoporous TiO2 modified with tungstosilicic acid as photocatalyst in the photodegradation of 4-chlorophenol
(Elsevier Science Sa, 2014-06-02)
Visible-light-absorbing materials based on TiO2 modified with tungstosilicic acid (TSA; H4SiW12O40) were prepared using titanium isopropoxide as precursor and urea as a low-cost pore-forming agent. X-ray diffraction (XRD) ...
Tungstophosphoric and tungstosilicic acids on carbon as acidic catalysts
(Elsevier Science, 2001-02)
Tungstophosphoric (TPA) and tungstosilicic acid (TSA) catalysts supported on carbon were studied. They were prepared by equilibrium and incipient wetness impregnation techniques. Solutions of TPA and TSA in 50% v/v ...
Synthesis and characterization of mesoporous H4SiW12O40/TiO2 composites
(Nova Science Publishers, 2009)
Mesoporous H4SiW12O40 /TiO2 composites were successfully synthesized by sol-gel reactions using urea as a low-cost template, and adding tungstosilicic acid (TSA) at the same time as the template. The prepared materials ...
2-Methoxynaphthalene acylation using aluminum or copper salts of tungstophosphoric and tungstosilicic acids as catalysts
(Elsevier Science, 2011-09-03)
Aluminum or copper salts of the tungstophosphoric (TPA) and tungstosilicic (TSA) acids were synthesized. They present interesting characteristics as catalysts because they can have Lewis and/or Brønsted acidity. The salts ...
Carbon-supported metal-modified lacunary tungstosilicic polyoxometallates used as catalysts in the selective oxidation of sulfides
(Elsevier, 2015-02-26)
Lacunary tungstosilicic polyoxometallates modified with transition metal ions [SiW11O39M(H2O)]6−, where M = Mn2+, Fe2+, Co2+or Cu2+, were synthesized and supported on activated carbon to obtain the SiW11MC catalysts. The ...
TiO2 modified with polyoxotungstates should induce visible-light absorption and high photocatalytic activity through the formation of surface complexes
(Elsevier Science, 2016-07)
TiO2 nanospherical particles prepared by the sol-gel method were modified with tungstophosphoric (TPA) and tungstosilicic acid (TSA) at 30% (w/w) and then annealed at 500 °C for 2 h. Materials were characterized by ...