| The use of solid acids, especially Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4,{dollar} to convert long chain alkanes and Fischer-Tropsch waxes to liquid fuels under mild reaction conditions was explored in this work. Anion and/or hydrogenation metal modified zirconium oxides were synthesized, characterized, and tested for hydrocracking and hydroisomerization of model compounds, chiefly with n-hexadecane. The relationship between catalytic activity and acidic character of the bifunctional Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4{dollar} catalyst was investigated.; Incorporation of small amounts of anionic groups, especially sulfate, enhances the surface acidic character of zirconium oxide. The catalytic activity of Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4{dollar} for acid-catalyzed reactions of long chain alkanes was strongly affected by the number and nature of its acid sites, and its acid strength.; The nature and amount of the hydrogenation metal has a great effect on the acidic properties and catalytic activity of ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4.{dollar} Pt doped ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4{dollar} exhibited high activity and selectivity to isoparaffins in hydrocracking and hydroisomerization of long chain alkanes including Fischer-Tropsch waxes at reaction temperatures between 433 and 443K, and 360 psig of hydrogen pressure. During the reaction, Pt not only prevented coke formation, but also dissociated hydrogen molecules into hydrogen atoms, which could spill over to Lewis acid sites, generating highly active protonic acid sites.; With an increase in hydrogen pressure or Pt loading, selectivity to cracked products increased with a concomitant decrease in selectivity to isomerized hydrocarbons. This catalyst was very active at hydrogen pressures between 300 and 1600 psig, with the highest activity occurring at 1600 psig of hydrogen pressure, without loss of the sulfate group.; Externally added olefins affect the reactivity and product selectivity of hydrocracking and hydroisomerization of hydrocarbons catalyzed by Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4.{dollar} Olefins with terminal double bonds interacted more strongly with acid sites than those with an internal double bond. Addition of a hydride transfer agent, such as adamantane or methylcyclopentane, not only enhanced the reactivity of Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4{dollar} but also increased selectivity to long chain isoparaffins (C9-C15 and isohexadecanes).; Product distribution of hydrocracking and hydroisomerization of n-hexadecane catalyzed by Pt/ZrO{dollar}sb2{lcub}rm /SO{rcub}sb4{dollar} obtained from the batch reactor was similar to that obtained from continuous fixed-bed reactors under similar reaction conditions. |
