Catalysts based on Zeolites brought revolution in oil refining and petrochemical production in recent years due to their size
selectivity and gained much research interest all over the world. The most well known and widely used zeolite is ZSM-5
(pores: 0.51 x 0.55 nm, 0.53 x 0.56 nm). ZSM-5 has been used successfully in aromatic isomerisation, methanol upgradation
and many other reactions in organic chemistry. On the other hand anhydrous aluminium chloride has been found to have a
high efficiency in isomerisation reactions due to its strong Lewis acidic nature. But application of this catalyst is limited due to
its high corrosiveness. In our present work we have used ZSM-13, which has not been normally used for catalyst preparation
as main matrix due to its high monobranching selectivity. And we have tried to increase its (ZSM-13) catalytic performance by
modifying the micropores present in it with aluminium chloride impregnation, reducing corrosive nature of aluminium chloride.
Three samples of aluminium chloride impregnated ZSM-13 containing 0.015, 0.025, 0.05 mol of anhydrous aluminium chloride
have been synthesized by batch impregnation method and thoroughly characterized by XRD, FTIR, SEM, TEM, AFM and BET
surface area analysis. Both XRD and FTIR analysis show that the pores present in the ZSM-13 sample is finely impregnated with
aluminium chloride. The SEM images of the samples show the surface morphology. Comparison shows that pure ZSM-13 has
some morphological change on the surface after impregnation with aluminium chloride. The TEM image of pure ZSM-13 shows
the micro pores present in it. The specific surface area of ZSM-13 has been increased after aluminium chloride incorporation.
This is very significant since the isomerisation reaction is very much sensitive to specific surface area. All the three samples
synthesized show very high conversion capacity of normal alkanes like n-hexane, n-octane compared to pure ZSM-13. This is due
to the increase in activity of the active sites present in pure ZSM-13 after incorporation of aluminium chloride. This enhanced
performance of aluminium chloride impregnated ZSM-13 also clearly indicates that pores present in ZSM-13 have not been
blocked by anhydrous aluminium chloride. Leaching test of the catalysts shows that aluminium chloride is not leached out from
any catalyst surface. Thus the aluminium chloride impregnated ZSM-13 sample is found to be very promising hydroisomerization
catalyst and can be very safely used for practical purpose.
Abhishek Dhar is a Junior Research Fellow in the Department of Chemical Technology, University of Calcutta. He is doing his research on the
preparation of hydroisomerisation catalyst of n-alkane. He qualified CSIR-NET and GATE exams and published 2 research papers in international
journals and presented papers in 4 international conferences.
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals