LAUSR

The trends in the development of acid catalysts for isomerization show that the diffusion and accessibility of products are more favored in mesoporous as compared to microporous materials. In this work, an easy metal alkoxide- and surfactant-free technique was developed to prepare mesoporous size-selective Pt/WO3–ZrO2 catalysts. A high-octane number blend was obtained in the nC6 isomerization reaction with these catalysts. The use of H2O2 produced an increase in the textural properties of the tungstated zirconia that generated a high expulsion of tungsten, significantly benefitting the development of Bronsted acid sites required in alkane isomerization reactions. Results show that these catalysts reached high conversion values (up to 85 mol%) and higher selectivity for bi-ramified isomers as compared to conventional tungstated zirconia (17 mol% for 2,2-dimethyl-butane and 13 mol% for 2,3-dimethyl-butane). The high catalytic activity is attributed to their improved mesoporous structure that allowed the formation of well-dispersed WOx clusters on the zirconia surface with an intermediate domain size. DFT calculations confirmed that intermediate WOx cluster sizes offer the best balance between the strength and number of Bronsted acid sites.