Support Composition and Annealing Temperature of NH4ReO4/Al2O3 – SiO2 System Effect Rhenium Heterogeneous Metathesis Catalyst Properties

NH4ReO4, supported in wt. 3.3% quantity on laboratory made amorphous aluminasilicas composed of wt. 20, 40, 60, 80 and 100%wt of Al3O3, was annealed at 200, 300, 400, 500, 600 and 700 graduate C for 2 h under air and 1 h under nitrogen. This way prepared catalysts, after modification with tetraethyllead (Et4Pb), were tested in the hexene-1 metathesis reaction. Both the support composition as well as calcination temperature affects the prepared catalyst activity. Low content Al2O3 catalysts are relatively more active when prepared by annealing at relatively lower temperatures. Contrary, the high content Al2O3 catalysts exhibit relatively higher activity after preparation at relatively higher temperatures. All catalysts, containing alumina-silica as supports and prepared between 300–500 graduate C, demonstrated the highest activity. When alumina is the catalyst support, the activity increased according to the calcination temperature growth.