Ceramic foams directly-coated with flame-made V2O5/TiO2 for synthesis of phthalic anhydride

Flame-made airborne V2O5/TiO2 nanoparticles were deposited directly onto mullite foam supports to create ready-to-use catalysts for the o-xylene conversion to phthalic anhydride. These particles containing 10% (w/w) V2O5 were created by combustion of liquid precursor sprays and characterized by transmission electron microscopy, nitrogen adsorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), and Raman spectroscopy. The specific surface area, anatase content, and dominantly monomeric vanadia species on titania were thermally stable up to 450 °C. Catalyst structure was controlled in situ during deposition by the particle-laden gas flow rate through the foam, resulting in homogeneous to patchy V2O5/TiO2 coatings. The catalytic activity and selectivity were affected by both coating texture and particle morphology. These flame-coated foams showed superior catalytic activity and selectivity at high conversions than classic, wet-made V2O5/TiO2 catalysts.