Methyltrioxorhenium on silica-alumina as metathesis catalyst of 1-octene

Methyltrioxorhenium (MTO) supported on silica-alumina acts as a heterogeneous catalyst for the metathesis of 1-octene. 7.5% (m/m) MTO on the support gave a maximum percentage of homo-metathesis products. The reaction reached equilibrium after 1.5 h at room temperature. Addition of cesium ions onto the silica-alumina support increased the selectivity towards homo-metathesis products but decreased the total metathesis activity. The optimum percentage of cesium ions on the support was found to be 3.3%. Addition of 1% oxygen-containing additives to the 1-octene like 2-hexanone, pentanal, butanol and pentanoic acid, increased the homo-metathesis products and decreased the cross-metathesis products of 1-octene catalysed by the MTO/SiO2. Al2O3 catalytic system. Higher concentrations of additives decreased the activity of the catalytic system. (C) 1999 Elsevier Science B.V. All rights reserved.