Synthesis and Characterization of Iron- and Vanadium-Doped Titania Aerogel Nanopowders

Abstract

Nanopowders of anatase FexV0.05Ti0.95−xOy (x=0, 0.02) solid solutions have been synthesized by a sol–gel process with ensuing supercritical drying. Changes in the surface state and crystal structure about the iron doping were characterized by X-ray photoelectron spectroscopy (XPS), electron spin resonance, and X-ray diffraction. XPS revealed an electronic interaction between Fe and V atoms in the ternary compound and the formation of Fe and V redox pairs on the surface. The oxide aerogels were evaluated as catalyst for methanol oxidation. Formaldehyde was favorably produced over the V-doped titania, and the Fe addition enhanced the rate of carbon oxides formation. Results demonstrate that the reducible Fe–O–V bond acts as active sites and influences product distribution. The competitive reactivity between Fe and V sites is responsible for the transformation of surface nature from redox to basic characters. The ceramic nanostructures are promising materials for use in many processes involving electron transfer.