PREPARATION OF IRON ZEOLITE CATALYSTS ACTIVE FOR TOLUENE DISPROPORTIONATION IN THE PRESENCE OF HYDROGEN-SULFIDE

Iron/zeolite catalysts were prepared by treating NH4Y-zeolite with aqueous solutions of ferric or ferrous salts. It was found that the catalysts prepared from the solution of ferric nitrate or sulphate exhibited high activity and selectivity for the toluene disproportionation reaction in the presence of hydrogen sulphide. Detailed investigations of the influences of preparation conditions, such as the kind of starting iron salt solution and treatment time, revealed that the iron species active for the toluene disproportionation could be supported on zeolite under such conditions that significant dealumination took place simultaneously from the zeolite framework. The spectroscopic evidence collected from Fourier Transform IR and X-ray diffraction suggested that the active species might be Fe3+ containing clusters which were bonded to zeolite framework.