New progress of Keggin and Wells–Dawson type polyoxometalates catalyze acid and oxidative reactions

Synthesis, Characterization and Catalytic Performance ofH3SiW12O40/SiIsahak1, Ismail2, Nordin3 et al. 2011Journal of Nanotechnology180140View full textAdd to dashboardCite

“…The W4f XPS spectra recorded from bulk STA (Figure 7(a)) composed of the spin-orbit doublet with binding energies for the W4f 7/2 and W4f 5/2 of 36.8 and 39.0 eV, respectively, with ΔBE = 2.13. These values were typical of the presence of W (VI) [11]. The W4f spectra recorded from STA-SG is less well resolved than that of STAB (Figure 7(b)).…”

“…The Dawson type STAB is formed by the combination of two Keggin molecules. The activity and stability of these catalysts depend on the structure and the type of the central atom along with the metal [10,11]. The STAB is impregnated onto different supports such as polymers and silica [12] to achieve high surface area and stability in polar solvents.…”

Encapsulation of Keggin-type phosphotungstic acid into the mesopores of SBA-16 as a reusable heterogeneous catalyst for the epoxidation of olefins

“…The major utilization of these compounds is in the area of catalysis where soluble POMs exhibit the role of homogeneous catalysts in the oxidation of organic compounds [5][6][7][8][9][10][11][12][13]. It is well-known that POMs have fast and reversible redox properties, which make them hopeful catalysts for the oxidation of ole ns, aromatics, and alcohols [14,15].…”

Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

“…The secondary structure is the three-dimensional arrangement consisting of polyanions, counter cations and additional molecules. The tertiary structure represents the manner in which the secondary structure assembles into solid particles and relates to properties such as particle size, surface area and pore structure (substituted heteropolyacid -HPA-for example) [9].…”