EFFECT OF MODIFICATION OF ZEOLITE HZSM-5WITH CERIUM OXIDE ON SELECTIVITY OF C2-C4OLEFINS FORMATION FROM METHANOL

Catalytic compositions containing 2.0-5.0 wt.% of cerium oxide were prepared on the basis of zeolite HZSM-5 and cerium oxide in order to increase the selectivity for lower olefins, and their acid, textural and catalytic properties in the conversion of methanol to C2-C4 olefins in the temperature range 250 0 -550 0 C at atmospheric pressure were investigated.It was shown by XRD, low-temperature nitrogen adsorption and thermoprogrammed ammonia adsorption methods that as a result of modification the zeolite structure is preserved, the modifier is dispersed on the outer surface and in the zeolite channels, and as a result of interaction of modifier nanoparticles with strong acid centres there is a decrease in the density of strong acid centres, an increase in the ratio of mesopores to total pore volume, which leads to an increase in selectivity for olefins C2-C4 and stability of the catalyst.High selectivity for propylene (39.7%) is achieved on the catalyst 4%CeO2/HZSM-5 at 550 0 C. Maximum selectivity for olefins (72.4%) and stability of operation (30 h) are achieved on the catalyst 5%CeO2/ HZSM-5.at 450 0 C.