Enhanced Olefin Metathesis Performance of Tungsten and Niobium Incorporated Bimetallic Silicates: Evidence of Synergistic Effects

Tungsten and niobium incorporated KIT‐6 (WNb‐KIT‐6) materials were synthesized by a one‐pot sol‐gel method. During 2‐butene+ethylene metathesis with these materials at 450 °C, the propene yield is maximized (∼70 %) at a certain metal composition (∼20 wt% W and ∼1 wt% Nb), significantly surpassing those reported with an industrial WO 3 /SiO 2 catalyst. The enhanced propene yield is attributed to better dispersion of W species on the catalyst surface and the formation of new active site precursors (O=) 2 W(O−Si)(O−Nb), as confirmed by XRD, TEM, H 2 ‐TPR, XPS, EXAFS, and ToF‐SIMS techniques. Complementary DFT calculations reveal a positive correlation between the O=W=O bond angle and the propene yield. We therefore speculate that the −O−Nb moiety tunes the electronic environment around the W atom and increases the propene yield.