Synthesis of lower olefins from C-3-C-4 alkanes on ZSM-5 zeolites modifiedwith alkali metals

It was shown that modification of ZSM-5 zeolites by alkali metals (except f or cesium) reduced their activity in the alkane conversion to olefins ton t he average, by three times at 600 degreesC) because of poisoning Broensted sites and simultaneously increased the selectivity with respect to the prod uction of olefins (ethylene and propylene) by a factor of 3. The conversion of lower alkanes proceeds according to the cracking mechanism. Addition of alkali metals as modifiers of zeolites of this type significantly hinders the occurrence of secondary reactions.