Clean gasoline reforming with superacid catalysts. Quarterly report, July--September 1991.

摘要

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.