Increasing the selectivity to ethylene in the MTO reaction by enhancing diffusion limitation in the shell layer of SAPO-34 catalyst.

The zinc cation accommodation in the cavities of the shell layer and the facilitated aromatic formation over the zinc cation modified SAPO-34 with a core-shell like structure introduce extra diffusion limitation for bulky hydrocarbons, which increases the selectivity to ethylene and the ethylene to propylene ratio at the initial stage of the MTO reaction.