Al2O3-Supported W–V–O bronze catalysts for oxidative dehydrogenation of ethane

Abstract

Supported vanadium-containing hexagonal tungsten bronzes (HTBs) were prepared for the first time using a combination of a new soft synthetic procedure and fine-tuned heat treatments. The characterization of heat-treated samples indicates that both unsupported and Al₂O₃-supported materials present mainly vanadium-containing crystals with HTB structure smaller in the supported materials. Raman, diffuse reflectance UV-visible and EPR spectroscopic results suggest the presence of different V species depending on the V loading and catalyst composition. When used as catalysts for ethane oxidative dehydrogenation (ODH), selected supported vanadium-HTBs show selectivity to ethylene as high as 80% at ethane conversion of around 18%. These values position these new materials among the most active and selective catalysts so far reported in the literature for ethane ODH over supported vanadium oxide catalysts.