Description: The data showing the selectivity for production of 1-octene during dehydration of 2-octanol for ZrO[sub 2]-A and for ZrO[sub 2]-A/S are shown in Figure 17. The unsulfated sample exhibits high selectivity for 1-octene initially, but this declines to stabilize at about 40% at a reaction temperature of 320[degrees]C. However, the selectivity of the sulfated sample for 1-octene is consistently high at a reaction temperature of 220[degrees]C. The addition of sulfate ions has therefore increased the catalytic activity over that of the unsulfated zirconia, and at the same time produced a catalyst that is very selective for 1-octene only. Thus, this ZrO[sub 2]-A/S sample clearly does not exhibit superacid character since the dehydration product is the least stable one. Under similar conditions, dehydration using amorphous silica-alumina produces an equilibrium distribution of m-alkenes. Samples of ZrO[sub 2]-N were sulfated and these catalysts were even more active for 2-octanol dehydration than ZrO[sub 2]-A/S. However, the sulfated samples based upon ZrO[sub 2]-N produced nearly 100% conversion at the highest flow rate possible with the equipment [LHSV=12] and showed an equilibrium distribution of normal octenes rather than a selectivity for 1-octene. The samples of sulfated zirconias that are described here show a wide range of activity compared to unsulfated zirconias, but none of them exhibits the chain isomerization character expected of a superacute.
Date: January 1, 1993
Creator: Davis, B. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department