With the rapid advancement of nanotechnology and with nanoparticles beginning to enter into products, the demand for production-level quantities of advanced nanopowders such as multi-component or coated oxides is rising. Such advanced nanoparticles can be effectively made by flame spray pyrolysis (FSP), and research with laboratory reactors yielded a spectrum of new nanomaterials for catalysis, pigments, ceramics, optics, energy and biomaterials, among others. Here, the transfer of FSP nanopowder synthesis from gram-level lab-scale to pilot reactors with up to 10 metric tons annual production rate is investigated by the example of FSP pilot plants that were realized in industrial-oriented settings. Design considerations for such pilot-scale systems are addressed and guides to production cost estimates are given. Special attention is brought to safe and contained nanoparticle manufacture in order to address the growing awareness of the potential health and environmental effects of nanoparticles.

The aerobic oxidation of cyclohexane was studied at 130°C in the presence of a Co/SiO 2 catalyst, synthesized by flame-spray pyrolysis. Characterization of the material indicates that at low Co-loadings, Co II is predominantly present as tetrahedral species, whereas at higher loadings also small amounts of octahedral species can be found at the surface of the agglomerated nanoparticles. Catalytic experiments demonstrate high activity, causing a complete in situ deperoxidation of the intermediate cyclohexylhydroperoxide. Hot-separation and catalyst-recycle tests corroborate the heterogeneous nature of the catalyst.

Flame-made airborne V 2 O 5 /TiO 2 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) V 2 O 5 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 V 2 O 5 /TiO 2 coatings. The catalytic activity and selectivity were affected by both coating texture and particle morphology. These flamecoated foams showed superior catalytic activity and selectivity at high conversions than classic, wet-made V 2 O 5 /TiO 2 catalysts.

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