Dp. Ivanov et al., Mechanism of coke influence on the catalytic activity of FeZSM-5 in the reaction of benzene oxidation into phenol, KINET CATAL, 41(6), 2000, pp. 771-775
The influence of coke formation in the reaction of benzene oxidation by nit
rous oxide into phenol on the catalytic activity and concentration of iron-
containing active sites (alpha -sites), which are stabilized in the micropo
rous structure of FeZSM-5 zeolite, is studied. The deactivation by coke is
explained by the poisoning of alpha -sites, whose concentration decreases l
inearly with an increase in the coke content, rather than by the blocking o
f zeolite pores. The activity per one alpha -site remains unchanged. This f
act indicates the absence of diffusion limitations associated with coke for
mation. The toxicity of coke for the alpha -sites is determined. The coke a
mount equivalent to 100-120 benzene molecules is shown to result in the dea
ctivation of one active site.