Insights into the monolayer formation on WO3/TiO2 catalysts for glycerol dehydration to acrolein

Abstract

The dehydration of glycerol to acrolein has the potential to increase the sustainability of acrolein production and its value chain. WO₃/TiO₂ has demonstrated good catalytic performance for this reaction, but an appropriate correlation of the catalyst properties with its activity is still missing. Thus, the influence of tungsten loading on WO₃/TiO₂ has been examined in terms of surface coverage and its subsequent effect on the catalyst acidity and activity. Different superficial species (monotungstates, polytungstates and crystalline WO₃) are present at different WO₃ loading as demonstrated using XRD, Raman, XPS and STEM. Moreover, increasing WO₃ loading resulted in enhanced Brønsted acidity, which positively impacted acrolein productivity. However, the formation of crystalline WO₃ at higher WO₃ loading compromises this positive effect by reducing the effective acid sites for acrolein formation.