Catalysis Letters, Vol.144, No.9, 1524-1529, 2014
Comparative Effect of Nano-Sized ZrO2 and TiO2 Additional Supports in Silica-Supported Tungsten Catalysts on Performance in Metathesis of Ethylene and 2-Butene to Propylene
The concept of thermal spreading has been adapted in this work to obtain special performance catalyst where the increase of conversion and selectivity were observed beyond the increase of coking. Nano-sized ZrO2 and nano-sized TiO2 were employed as an additional support to be physically mixed with WO3/SiO2 catalysts and heated under thermal condition before being investigated in the metathesis reaction of ethylene and trans-2-butene to produce propylene. The presence of tungsten was found on the separated nano-sized ZrO2 and TiO2 supports evidenced by ICP-OES, confirming thermal spreading of tungsten oxide species. The dispersion of WOx examined by FT-Raman and UV-Vis for WO3/SiO2 catalysts mixed with ZrO2 was better than the ones mixed with TiO2. The nano-sized ZrO2 chosen as an additional support having higher surface energy than the nano-sized TiO2 was shown to provide differentiating the catalytic performances where trans-2-butene conversion could be boosted up together with propylene selectivity with lesser amount of coke even higher acidity.