D. P. Ivanov et al.
FULL PAPERS
Table 6. Characteristics of FeZSM-5 zeolite.
Structure
Chemical composition (wt %)
Texture parameters
Ca
Al
Fe
Na
Vm [cm3/g]
0.160
ABET [m2/g]
430
Aext [m2/g]
70
(a-site/g)
5.5 ¥ 1017
MFI
0.9
0.02
0.03
having 50mol % H 2O. The a-sites concentration of the
activated sample, measured by N2O decomposition and
oxygen isotopic exchange, is 5.5 ¥ 1017 site/g.
by the COx concentration in the gas phase. Coke amount was
calculated from the total amount of CO and CO2 produced.
Some control experiments with the coke measurements by the
TGA technique showed well-consistent results. Regeneration
of the catalyst provides complete restoration of its activity.
Procedures for measuring the zeolite characteristics are
described in more detail elsewhere.[22]
Acknowledgements
Catalytic Studies
The authors thank Solutia Inc. for permission to publish these
data.
Flow setup: Catalytic experiments were carried out with an
automated flow setup provided with on-line chromatographic
analysis of the gas phase. 2 ccm (~1.1 g) of the 0.5 1.0 mm
catalyst particles were placed into a quartz reactor with an
inner diameter of7 mm. Before testing, the catalyst was treated
in flowing air at 550 8C. Gases were fed by the flow mass
controllers (MKS Instruments), the liquid phenol-benzene
mixture of the given composition was fed using a high-
performance syringe pump 500 D (ISCO).
The reaction mixture was automatically sampled and
analyzed each 19 min. The light gases (N2, N2O, CO, CO2)
were analyzed at room temperature with a packed column
filled with Poropak Q, using a TCD. For a more accurate
measurement of low COx concentrations, carbon oxides were
hydrogenated over a nickel catalyst and then analyzed as
methane using FID. Analysis of organic components was
performed at the programmed temperature elevation from 180
to 280 8C with a capillary column DB-1701 (J&W Scientific)
using FID.
References
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