Nanocasting of Ordered Mesoporous Co(3)O(4)-Based Polyoxometalate Composite Frameworks
(EN)
Armatas, G. S.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Armatas, G. S.
(EN)
We report the synthesis of highly ordered mesoporous frameworks consisting of nanocrystalline Co(3)O(4) and Keggin-type tungstophosphoric acid (HPW(12)O(40), HPW) compounds using the hard-templating method. The resulting materials feature a Co(3)O(4)/HPW solid solution structure with different HPW loadings, i.e., 6, 11, 15, and 36 wt %. Characterization by small-angle X-ray scattering (SAXS), high-resolution transmission electron microscopy (TEM), and N(2) physisorption measurements reveal that all mesoporous frameworks possess a three-dimensional cubic symmetry with large internal Brumauer-Emmett-Teller (BET) surface area (87-141 m(2)g(-1)) and narrow sized pores (ca. 4 nm). The Keggin structure of the incorporated PW(12)O(40)(3-) clusters within the composite frameworks was confirmed with X-ray diffused scattering and atomic pair distribution function (PDF) analysis, X-ray photoelectron spectroscopy (XPS), infrared (IR), and diffuse-reflectance UV/vis spectroscopy. Catalytic studies have indicated that these Co(3)O(4)/HPW composites can be effective catalysts, exhibiting remarkable catalytic activity on direct decomposition of N(2)O.
(EN)
