| 초록 |
Two type ZSM-5 catalysts (Si/Al ratio of ∼30) with different mesoporosity were prepared by changing the molar compositions of the synthetic precursor. The prepared ZSM-5 with high and low mesoporosity were denoted H_30 and _L30, respectively. From the acid titration, it was confirmed that H_30 contained internal Brønsted acid sites similar to commercial ZSM-5 having Si/Al ratio of 75 (denoted as C_75), though H_30 had a large amount of external Brønsted acid sites. According to the MTH reaction performance, it was confirmed that H_30 favored producing propene over ethene compared to C_75, while L_30 was inactive on MTH reaction due to the lower amount of internal Bronsted acid sites. Concretely, a short diffusional length resulted from the mesoporosity suppressed the dealkylation of aromatics, resulting in high propene/ethene (P/E) ratio. Moreover, ceria doping on the H_30 was conducted to passivate the external Brønsted acid sites, resulting in both high stability and P/E ratio. |
