Romain Delaigle

Ag-V2O5/TiO2 total oxidation catalyst: autocatalytic removal of the surfactant and synergy between silver and vanadia

Silver nanoparticles prepared at room temperature in multilayer organic vesicles are deposited onto a V2O5/TiO2 support to produce a bifunctional oxidation catalyst performing very well in the total oxidation of benzene. The synergy between Ag and V2O5 takes place only when the surfactant is eliminated by in situ calcination. This paper shows that vanadium oxide autocatalytically promotes the combustion of this organic matter. This effect allows treating the catalyst at lower temperature which leads to an enhanced doping effect of the small tailored Ag nanoparticles, presumably because sintering is avoided.

Design of nano-sized FeOx and Au/FeOx catalysts for total oxidation of VOC and preferential oxidation of CO

The total oxidation of methanol and toluene, chosen as representative VOCs, was investigated over CeO2-supported Au/FeOx catalysts prepared utilizing the bimetallic carbonyl cluster salt [NEt4][AuFe4(CO)16]. Characterization data showed that the catalysts prepared by the reported method exhibit highly and homogeneously dispersed iron oxide species on the ceria support together with small gold nanoparticles, whose size increases on increasing the amount of gold/iron. Addition of iron oxide species did not substantially increase the methanol combustion activity of ceria, whereas the presence of the mixed gold and FeOx species has been found to strongly enhance the activity towards the total oxidation of methanol. In the case of the toluene combustion the addition of FeOx or FeOx/Au species caused a significant decrease in the activity of the bare CeO2. The above catalytic behavior was rationalized on the basis of different interactions occurring among gold, iron oxide and cerium oxide, which synergically affects both the reactivity of the surface oxygen and the capacity of the support to adsorb the organic reactant.