Effect of Support on Metathesis of n‐Decane: Drastic Improvement in Alkane Metathesis with WMe5 Linked to Silica–Alumina

[WMe₆] ( 1 ) supported on the surface of SiO₂–Al₂O₃₍₅₀₀₎ ( 2 ) has been extensively characterized by solid‐state NMR spectroscopy, elemental analysis, and gas quantification, which clearly reveal the formation of a mixture of monopodal and bipodal species with the migration of methyl from W to Al. The supported species SiO₂–Al₂O₃₍₅₀₀₎ ( 2 ) transformed at 120 °C into two types of carbynic centers, one of which is cationic and the other neutral. These species are very efficient for the metathesis of n‐decane. Comparison with already‐synthesized neutral bipodal tungsten indicates that the high increase in activity is due to the cationic character of the grafted tungsten.