INVESTIGATION ON THE KINETICS OF DIFFUSIO N OF ETHENE ON 4A ZEOLITES

The kinetics of diffusion of ethene on 4A zeolites was examined. Concl usions on the transport mechanism were obtained by the loading depende nce on the diffusion coefficients. Contrary to propene and the n-buten e isomers, ethene can cross the windows to the cavities blocked up by Na+ ions in the NaA and Me0,22+Na0,8A zeolites (Me = Mg, Ca, Zn, Ba) b y a translatory jump motion. In NaKA zeolites - by reason of additiona l blocking up of windows with K+ ions - the ethene molecules overcome the barrier only through the ethene/Na+(1) addition complexes.