Sh. Baeck et al., SKELETAL ISOMERIZATION OF 1-BUTENE INTO ISOBUTENE OVER MG-ZSM-22 MODIFIED BY THE DEPOSITION OF SILICON ALKOXIDE, Catalysis letters, 52(3-4), 1998, pp. 221-225
Mg-ZSM-22, modified by the deposition of silicon ethoxide, was prepare
d and investigated as a catalyst for the skeletal isomerization of 1-b
utene to isobutene in a fixed-bed flow reactor. The prepared catalysts
were characterized by XRD, TPD, SEM-EDX, ICP and FT-IR.; The depositi
on of silicon alkoxide on Mg-ZSM-22 led to a decrease in the amount of
strong acid sites, confirmed by TPD experiments with ammonia and gamm
a-collidine. The treatment also affected the size of pore opening, as
evidenced by constraint index measurement and chemisorption experiment
using n-hexane. As the deposition time increased, the conversion of 1
-butene decreased as the result of reduced acidity, while selectivity
to isobutene increased. The deposition of silicon alkoxide resulted in
the suppression of side reactions and coke deposition, thus enhancing
the skeletal isomerization. The modification of Mg-ZSM-22 by depositi
on of silicon alkoxide was very effective in terms of catalytic stabil
ity and coke removal.