(66b) Isomerization of Hexane on Pt-Au Nanoparticles Supported on Zeolites

Authors: 
Fraissard, Sr., J. - Presenter, University of Pierre and Marie Curie
Gerda, V. - Presenter, Taras Shevchenko National University
Patrylak, K. I. - Presenter, Institute of Biorganic Chemistry and Petrochemistry
Voloshyna, Y. G. - Presenter, Institute of Biorganic Chemistry and Petrochemistry


It is planned to eliminate benzene and its derivatives from petrol and to replace them by methylated hydrocarbons, whence the importance of the isomerization of n-alkanes, which is currently performed in liquid superacid media, since current solid superacids are very rapidly poisoned. We show that some Pt-Au based zeolite catalysts can be useful in this reaction.

Samples were prepared according to reference [1] with 1% w/w of Pt and a ratio Au/Pt=20. UV-Visible, microtomy-EM and EDX spectroscopies show that the particles are essentially in the pores and are bimetallic.

The hydroisomerization of hexane was carried out at 200-350°C in a flow-type fixed-bed reactor. HY, Pt?HY and PtAu-HY are of no interest for this reaction. The efficiency of PtAu-HZSM5 is noteworthy; it is remarkably stable over one week with a selectivity and an activity for methylpentane of about 80% at 260°C. Moreover, cracking is negligeable, the other reaction products being i-C5 and i-C4.

[1] Riahi G., Guillemot D., Polisset-Thfoin M., Khodadafi A., Fraissard J., J. Catal. Today, 72, 115 (2002)