Pt COLLOIDAL NANOCATALYSTS
789
the preparation of the colloids. The initial rate is high because
there is no (or little) agglomeration of the colloidal nanoparticles
with no pause of the stirring, and it should drop dramatically
with more agglomerated colloidal particles when the stirring
paused during the preparation of the colloids. The average rates
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4. CONCLUSIONS
PVP–Pt colloids were prepared by varying preparation con-
ditions. The average diameter and standard deviations of PVP–
of aromatic chloronitro compounds. Curr. Org. Chem., 2007, 11(3), 299–
314.
14. Yu, W.W., and Liu, H. Singular modification effects of metal cations and
Pt colloids were affected remarkably by the interval that the
stirring was paused in the preparation procedure. They both in-
creased when the pause time was lengthened, and there was
serious agglomeration of the colloidal particles when the stir-
ring was paused for 30s. The catalytic performance and the
morphology of the colloidal particles were dependent on their
synthesis method. The conversion of MCB over PVP–Pt pre-
pared without pausing the stirring was 99.34% at 10 hrs reac-
tion time, and the main product was cyclohexane. In contrast,
the conversion and the selectivity to cyclohexane decreased to
79.06% and 74.40%, respectively, with 30s pause of the stirring.
This study highlights the importance of stirring in the prepara-
tion of polymer-stabilized nanoparticles and its dramatic effect
on the resultant colloidal particles’ catalytic activity and selec-
tivity in hydrogenation of chlorobenzene, which should prove
valuable for the future development of a reliable and efficient
hydrodechlorination of organic pollutants.
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