Electrospun Mo-SiO2 Nanofibers as Heterogeneous Catalysts for Propylene Metathesis

Olefin metathesis catalysts based on molybdenum display superior performance at low temperatures when exhibiting highly dispersed MoOx species within the catalyst support. These preparation methods are unfortunately not easily scalable. This study presents the synthesis of molybdenum silicate (Mo-SiO2) nanofibers via electrospinning, aiming for scalable preparation of catalysts active in olefin metathesis reactions. The prepared nanofibers exhibited diameters ranging from 70 to 209 nm and high surface areas reaching up to 922 m² g−1. A thorough study on MoOx active sites, revealing absence of crystalline phase indicative of high uniformity was conducted by PXRD, Raman spectroscopy, XPS, HRTEM, H2-TPR, and in situ DRUV-Vis. The Mo-SiO₂ with 5 wt% of Mo, with an average diameter of 104 nm and a surface area of 456 m² g−1, demonstrated outstanding catalytic activity in propylene self-metathesis, achieving an ethylene production rate of 17.1 μmol g⁻¹ s⁻¹ at 200 °C and significantly overpassed incipient wetness impregnation catalyst (IWI) employed as model for industrial catalysts.