Effect of Reduction on the State of the Surface Layer and Catalytic Properties of \({{{\text{Pt}}} \mathord{\left/ {\vphantom {{{\text{Pt}}} {{{{\text{WO}}_{4}^{{2 - }}} \mathord{\left/ {\vphantom {{{\text{WO}}_{4}^{{2 - }}} {{\text{Zr}}{{{\text{O}}}_{2}}}}} \right. \kern-0em} {{\text{Zr}}{{{\text{O}}}_{2}}}}}}} \right. \kern-0em} {{{{\text{WO}}_{4}^{{2 - }}} \mathord{\left/ {\vphantom {{{\text{WO}}_{4}^{{2 - }}} {{\text{Zr}}{{{\text{O}}}_{2}}}}} \right. \kern-0em} {{\text{Zr}}{{{\text{O}}}_{2}}}}}}\) in the Hydroisomerization of an n-Heptane–Benzene Mixture

Resumo

Results of a study of the catalytic properties of platinum-containing tungstated zirconia in the hydroisomerization of an n-heptane–benzene mixture as a function of the reduction temperature of the catalyst in a hydrogen medium have been described. The main products of n-heptane conversion are di- and monomethyl-branched heptane isomers, and benzene is hydrogenated to cyclohexane, which undergoes isomerization to methylcyclopentane. It has been shown that an increase in temperature above 300°C leads to a significant decrease in the catalyst activity, while the parameters of the crystalline and pore structure of the catalyst remain stable. Using X-ray photoelectron spectroscopy, it has been found that an increase in the reduction temperature leads to an increase in the concentration of tungsten and platinum reduced to the metallic state on the catalyst surface.