Germanium and silicon compounds as promoters for Re 2O 7/SiO 2-Al 2O 3 metathesis catalysts

Abstract

The effect of replacement of R 4Sn by germanium and silicon derivatives as the promoter for the catalyst system Re 2O 7/SiO 2-Al 2O 3 in the metathesis of hex-1-ene, and the system Re 2O 7/B 2O 3/SiO 2-Al 2O 3 in the metathesis of methyl oleate, was studied. The new promoters react slowly with the rhenium oxide. An activation time of about 15 min at temperatures varying from 50 to 75 °C is required for obtaining a good catalytic activity. These promoters can replace the toxic tin compounds, although they give rise to lower turnover numbers in the metathesis of methyl oleate.