Optimizing activity of tungsten oxides for 1-butene metathesis by depositing silica on

[محمد بهبهانی]

a b s t r a c t
A series of catalysts made of tungsten oxide loaded on SiO2, -Al2O3, SiO2–Al2O3 and silica deposited -alumina
are tested for 1-butene metathesis. Among these catalysts, the catalyst 6W/20SiO2/Al2O3 gives the highest activity
for 1-butene metathesis reaction with 1-butene conversion up to 71mol% and the yield of propene up to 21 mol%.
The excellent catalytic activity is related to the moderate dispersion of tungsten oxide and the suitable acidity of
the support. The dispersion of WOx species and the acidity of supports were studied by characterization of XRD,
Raman spectra, UV–vis, H2-TPR and NH3-TPD in detail. The surface properties of silica modified -alumina leads to
the moderate aggregation of supported tungsten oxide, which appears to be more effective for 1-butene metathesis
at the low temperature of 453 K. Optimized activity was realized by tuning the dispersion of tungsten species on
silica deposited alumina.

Keywords: 1-Butene; Metathesis; Silica modified -Al2O3; Tungsten oxide