Comparative photocatalytic behavior of Ta catalysts prepared by d.c.-sputtering, sol–gel and grafting in acetone degradation

Synthesis and high temperature XRD studies of tantalum nitride thin films prepared by reactive pulsed dc magnetron sputtering

“…It is found that the surface of the sample contains both cuboidal and elliptical shaped crystallites with the root mean square (RMS) roughness of 1.9 nm for the films deposited in pure argon atmosphere ( Fig. 6(a)) [22]. When nitrogen was introduced into the chamber, the round shape grains were getting coarsening and the surface roughness was lightly increased (Fig.…”

Enhancement of Epoxidation Efficiencies for Ta-SBA15 Catalysts. The Influence of Modification with –EMe3 (E = Si, Ge, Sn) Groups

“…Heterogeneous group 5 metal catalysts are known to be active for a variety of oxidation reactions. − However, few studies have focused on supported tantalum(V) materials as alkene epoxidation catalysts. ,,− Previous work in our laboratory explored surface modification of supported transition metal catalysts for the oxidation of alkenes with aqueous H 2 O 2 . ,, Catalysts modified with –OSiR 3 groups were found to be highly selective in the epoxidation of cyclohexene, possibly due to the hydrogen bonding interaction of a trialkylsilanol group with the proposed metal-peroxo or metal-hydroperoxo intermediate (Scheme ). Along these lines, hydrogen bonding interactions involving metal-peroxo species have been calculated to be critical for oxidation reactions in fluorinated solvents and in metal-based oxidation reactions. , Thus, substituent effects on such hydrogen-bonding interactions are worthy of further examination.…”