Isomerization of hexane on PtAu nanoparticles supported on zeolites

When lead-based anti-knock additives were withdrawn, petrol was enriched with benzene and benzene derivatives in order to maintain an excellent octane number. However, because of their toxicity, it is planned to eliminate these also and to replace them by methylated alkanes, whence the importance of n-alkane isomerization. Some PtAu-zeolite catalysts tested for n-hexane isomerization reveal that the addition of gold to platinum generally changes the activity and/or the selectivity for methylpentane to the detriment of cracking. The influence of the zeolite structure is also important. At 275 °C, the activity and selectivity of PtAu-HZSM5 are about 75%, showing that this catalyst can be useful for such a reaction.