The formation of the crystalline structure and textural properties of zirconia during the thermal activation of a hydroxide precursor with additives of tungstate anions at temperatures of 600-870°C has been studied. It has been found that, in the application of the different methods of mixing (coprecipitation or impregnation) of tungstate anions and zirconium hydroxide in the amount of more than 12.9 mol %, a dispersed phase of tetragonal zirconia having a mesoporous structure with a pore size of 7-8 nm is formed during thermal treatment. The catalytic activity of Pt/WO4~(2-)/ZrO2 in the isomerization of n-hexane and n-heptane depends in a nonmonotonic mode on the concentration of tungstate anions. In both reactions at a low temperature, high yields of isomers with a selectivity of at least 87% are achieved on the catalyst that has been prepared by impregnation and contains 17.6 mol % WO4~(2-).
展开▼
