| 초록 |
Two type MFI catalysts (Si/Al ratio of ∼30) with different mesoporosity were synthesized by using a structure directing agent of tetra-n-butylphosphonium hydroxide and differing the molar compositions of ethanol and water in the synthetic precursor. The resulting MFI catalysts were comprised of very thin pillars and layers; (1) H_30 (high mesoporous MFI) and (2) L_30 (low mesoporous MFI). From pyridine and dTBPy adsorbed FT-IR result, we found that H_30 and C_75 (Si/Al ratio of ~75) had similar internal Brønsted acid sites, but only H_30 has a large amount of external Brønsted acid sites. At the methanol to hydrocarbons (MTH) reaction performance, H_30 produced high ratio of propene to ethene more than C_75, but L_30 showed a very poor MTH performance. Furthermore, Ce-doping on H_30 improve the ratio of propene to ethene up to ∼15.0 and enhance the stability of catalyst during MTH reaction via passivating external Brønsted acid sites. |
