surface of mesostructured silica, kit-6, was modified by grafting 3-aminopropyl-triethoxysilane (aptes) to have the positive charge, and thus, to provide sites for the immobilization of h3pw12o40 (pw12).  this modified-nanosized mesoporous silica (pw12-aptes@ kit-6) was characterized by ftir, xrd, bet and tem. the oxidation of sulfides occurs effectively and selectively with h2o2 as the oxidant...

Keggin-type polyoxometalate (POM), phosphotungstic acid (H3PW12O40), was encapsulated by an oppositely charged COOH-functionalized surface active ionic liquid (SAIL), N-decyl-N′carboxymethyl imidazolium bromide ([N-C10, N′-COOH-Im]Br), with the assistance of an ionic self-assembly (ISA) process in an aqueous environment. The as-prepared POM/SAIL material possesses multiple active properties, in...

Heterogeneous catalysis and their application in industrial-scale organic synthesis of fine chemicals are greatly facilitated by catalysis and further on by catalyst recovery and recycles to fits most “principles of green chemistry. In acid media, terpenoids generally undergoes various transformations. The terpenoid transformations include various liquid Bronsted and Lewis Acids, Acid clays, He...

A series of HPW/CeO2 catalysts generated from 12-tungstophosphoric acid, H3PW12O40 (HPW), supported on ceria and presenting different tungsten loadings (2, 4.5, 9, 16, 40 wt% W) were prepared characterized by N2 physisorption, XRD, IR, Raman, UV-Vis. The characterization techniques suggested that low loading resulted in mainly isolated sites, while high produced polymeric or clusters. Those mat...

The main objective of this work was to design an innovative method prepare heterogeneous heteropolyacid catalysts. H3PW12O40 (HPW) modified with tin(II) by two methodologies: a conventional aqueous ion-exchange (CS) and redox solid-state (SS). In both cases, Fourier transform infrared spectroscopy (FTIR) X-ray diffraction (XRD) measurements evidenced that Keggin structure preserved. All materia...