Catalytic coatings for structured supports and reactors: VO x/TiO 2 catalyst coated on stainless steel in the oxidative dehydrogenation of propane

Abstract

The catalytic properties of VO x /TiO 2 when coated as a thin layer on stainless steel plates figuring out the walls of a reactor were studied in the oxidative dehydrogenation of propane to propene. The method to obtain mechanically stable but catalytically active and selective coatings consisted of dip-coating plates in titanium oxide suspension, followed by grafting of oxovanadium precursor specie in various amounts. In that way the textural and structural properties of coated plates were very similar to those of VO x /TiO 2 powders of the same composition as seen from Raman and XPS experiments. The catalytic properties were investigated in a specially designed plate reactor and compared to those of the same catalyst used as powders in a conventional fixed bed reactor. The lower activity of plates vs. powders for the same composition and amount of active phase was attributed to the negative role played by iron diffusing towards the surface and poisoning the vanadate specie.