High-throughput study of the iron promotional effect over Pt/WO _x-ZrO ₂ catalysts on the skeletal isomerization of n-hexane

Pt supported on tungstated zirconia catalysts (Pt/WZ) doped with different Fe contents were evaluated in the n-hexane hydroisomerization reaction. High-throughput experimentation (HTE) approaches were used to investigate the effect of the iron incorporation over the catalytic activity. It was found that the presence of iron at low concentrations (0.5-1 wt%) increases the conversion and the yield to the high octane 2,2-dimethyl-butane (2,2-DMB) isomer. The characterization results suggest that the presence of iron modifies the nanostructure of the WO _x species on the zirconia surface which in turn produces the generation of active Bronsted acid sites thus optimizing the tungsten content toward the highest catalytic activity. It was also found that the surfactant incorporation further improves the performance of Pt/WZ catalysts, although, the activity was improved with the Fe addition at lower concentration.