Deep Oxidation of Benzene, Toluene and Xylene by Hydrophobic Pt Catalysts

This research is to investigate the deep
oxidation of benzene, toluene and xylene
(BTX) on Pt hydrophobic catalysts. Active
carbons were pretreated under 400 ℃, 800 ℃
and HF washing, then labeled as AC400,
AC400HF, AC800 and AC800HF. The 0.3
wt% Pt catalysts were prepared using
H 2 PtCl 4 by incipient wetness method,
following H 2 reduction at 300 ℃ for 2 hours. The complete oxidation temperature of BTX
ranges from 130-190 ℃. The temperature of
completely oxidation from low to high is
benzene, toluene and xylene. Benzene and
toluene are completely oxidized at 130-160
℃using Pt/AC800 and Pt/AC800HF in dry
condition, while the complete oxidation is
at160-190 ℃ using Pt/AC400 and
Pt/AC400HF. For all catalysts, the complete
oxidation is in the range of 160-170 ℃
under 6% water in the feed. Less difference
of catalytic activities is found in humid
condition. Above 150 ℃, the amount of BTX
adsorptions in AC800 and AC800HF are
higher than those of AC400 and AC400HF
from TGA. A mechanism is proposed that
adsorbed BTX migrate to Pt site, and are
oxidized by O 2 . Therefore the oxidation
activity of BTX is enhanced by the
hydrophobic active carbon.