TITLE:
Oxidative Dehydrogenation of Ethylbenzene over ZSM-5 Type Chromosilicates in the Presence of CO2
AUTHORS:
Ebrahim Sadeghi, Maryam Saket Oskoui, Maasoume Khatamian, Abdolhossein H. Ghassemi
KEYWORDS:
Chromosilicate, Styrene, Ethylbenzene, Dehydrogenation, Chromium Oxide
JOURNAL NAME:
Modern Research in Catalysis,
Vol.5 No.3,
June
30,
2016
ABSTRACT: In this work, ZSM-5
type chromosilicate samples as K[Cr]ZSM-5(KCS) and Na[Cr]ZSM-5(NCS) were prepared
by hydrothermal method and their catalytic properties were investigated for the
oxidative dehydrogenation of ethylbenzene in the presence of CO2 as
an oxidant using a fixed-bed stainless steel reactor. The prepared samples were
characterized by their morphology (SEM), structural parameters (XRD), and
textural parameters (BET). The performance of these catalysts was evaluated in
terms of conversion, styrene yield, and selectivity. The KCSBW catalyst (potassium chromosilicate before washing with distilled water)
afforded the highest styrene yield, 56.19%, with the selectivity of 96.05% in
the presence of CO2 because of the coexistence of potassium ion and
Cr2O3 in its structure and their synergistic effect. The
influence of the presence of Cr2O3 and sodium or
potassium ion on the catalytic activity of the chromosilicate samples in the
catalytic EB dehydrogenation process was discussed in detail. Moreover, according
to the results, the catalytic activity of the chromosilicate samples (CS) in EB
dehydrogenation was increased by decreasing the surface area.