| 초록 |
Highly selective production of propylene in the ethylene-to-propylene (ETP) reaction is required to manage the supply-demand balance of light olefins in the petrochemical industry. Herein, heteroatom-incorporated SSZ-13 zeolite catalysts showed the increased selectivity and yield of propylene in the ETP reaction compared with the untreated catalyst. The modified catalysts were characterized using NH3-TPD, TPD-MS, STEM-EDX, and rate of adsorption measurements. It was found that the improved production of propylene was predominantly attributed to the decrease of diffusivity of C4+ species in the catalyst, instead of the passivation of external acid sites. The heteroatoms were mainly located on the surface of SSZ-13 crystals, thus inhibited the diffusion-out of bulky C4+ species from the catalyst without interfering the diffusion of C2 and C3 species. Therefore, the number of chemical species that participate in the reaction cycle of propylene generation could be significantly increased. |
