Sentence examples for active surface vanadia from inspiring English sources

Crystalline anatase was not found to be necessary for the formation of active surface vanadia species.

For supported vanadia catalysts, the active surface sites were essentially redox sites, with the exception of supported V2O5/Al2O3 that also contained strong acidic sites.

Methanol chemisorption studies demonstrated that a similar number of active surface sites are present in the supported vanadia and niobia catalyst systems.

The TiO2 support was also found to be active for this reaction, but its activity was significantly lower than that of the surface vanadia species.

Surface vanadia coverage has a clear effect on TOF and activation energy values, which underline that isolated vanadia species are more efficient for o-DCB oxidation, while the polymeric ones are more efficient for NO reduction.

The ability of K2O to significantly retard the redox potential of the surface vanadia species is primarily responsible for the lower catalytic activity of the ternary catalytic system.

Shorter depositions gave surface vanadia monomers and polymers, whereas for longer depositions, crystalline species developed on either support.

Ceria- and niobia-supported vanadia catalysts do not follow this trend due to solid-state reaction between the surface vanadia species and the oxide support that decreases the number of exposed vanadia sites.

The supported vanadia catalysts possess only surface vanadia species coordinated with titania and/or silica, alumina and tungsten in the corresponding catalysts.

The reducibility of surface vanadia species was studied by H2-TPR.

Surface vanadia species remain essentially oxidized during the steady-state ethane oxidation reaction.