Abstract:
Alkylation of toluene with methanol was investigated on MFI-type zeolite catalysts containing Fe or Zn within the range of 0-2% as an active component. The catalytic performances were compared on catalysts to which Fe or Zn was introduced by different method, i.e. ion-exchanged and incorporation method. The prepared catalysts were characterized by XRD, XRF, BET, FTIR and pyridine adsorption technique on in-situ FTIR. The results show that both H-Fe, Al-silicate (Si/Fe = 150) and H-Zn, Al-silicate (Si/Zn = 150) exhibited catalyst activity and xylene selectivity approximately comparable with those of Fe(0.8)/H-MFI and Zn(1.0)/H-MFI with nearly the same amount of the corresponding Fe or Zn. The higher p-xylene distribution was achieved with H-Fe, Al-silicate (Si/Fe = 150) and H-Zn, Al-silicate (Si/Zn = 150) because of the weaker Bronsted acid strengths than those of Fe(0.8)/H-MFI and Zn(1.0)/H-MFI. Therefore, the isomerization of p-isomer produced primarily was suppressed by H-Fe, Al-silicate(si/Fe = 150) and H-Zn, Al-silicate (Si/Zn = 150) better than by Fe(0.8)/H-MFI and Zn(1.0)/H-MFI.
