Catalytic coatings for structured supports and reactors: VOx/TiO2 catalyst coated on stainless steel in the oxidative dehydrogenation of propane

The catalytic properties of VOx/TiO2 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 VOx/TiO2 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.

The catalytic properties of thin films of VOx/TiO2 coated on stainless steel plates in the oxidative dehydrogenation of propane to propene were investigated in a specially designed reactor. Structural characteristics and catalytic properties were compared to those of VOx/TiO2 powders of the same composition.Figure optionsDownload high-quality image (151 K)Download as PowerPoint slideResearch highlights▶ Improved heat and mass transfers can increase selectivity in oxidative dehydrogenation of propane. ▶ Well characterized VOx/TiO2 coatings onto stainless steel plates were prepared. ▶ Structural properties of VOx/TiO2 plates were compared to VOx/TiO2 powders. ▶ Catalytic properties in plate reactor and in fixed bed reactor were compared. ▶ Poisoning by iron is the main reason why plates were less selective than powders.