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

A series of catalysts made of tungsten oxide loaded on SiO2, γ-Al2O3, SiO2–Al2O3 and silica deposited γ-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 71 mol% 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 γ-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.

Silica deposited γ-Al2O3 with properly tuned acidity offered the moderately aggregated size of the WOx species, which are fairly active for 1-butene metathesis at the low temperature of 453 K.Figure optionsDownload high-quality image (309 K)Download as PowerPoint slideHighlights
► Tunable acidity of support is realized by doping silica to γ-Al2O3.
► Moderate poly-tungsten species supported on silica-doped γ-Al2O3 shows fairly good activity for 1-butene metathesis at the low temperature of 453 K.
► Good stability was also presented.