| 학회 |
한국화학공학회 |
| 학술대회 |
2013년 가을 (10/23 ~ 10/25, 대구 EXCO) |
| 권호 |
19권 2호, p.2097 |
| 발표분야 |
촉매 및 반응공학 |
| 제목 |
Effect of Temperature on the Crystallization of Zeolites UZM-5 and UZM-9: An Investigation of the Charge Density Mismatch Barrier |
| 초록 |
The crystallization processes of zeolites UZM-5 and UZM-9 at two different temperatures (150 and 100 °C, respectively) in the simultaneous presence of tetraethylammonium (TEA+), tetramethylammonium (TMA+), and Na+ ions as structure-directingagents (SDAs) are compared in order to investigate the influence of temperature on the barrier to charge density mismatch (CDM) zeolite synthesis. At 150 °C, TEA+ plays a critical role in overcoming the barrier associated with the conversion of soluble TEA+-aluminosilicate species to yield UZM-5 crystals with a considerably higher Si/Al ratio (ca. 7 vs 3) and a notably higher solid yield (ca. 45 vs 20 wt %) compared with those of UZM-9 crystallized at 100 °C. While the presence of Na+ is required for overcoming the CDM barrier at 100 °C to UZM-9 crystallization, on the other hand, TMA+ is the key SDA in the nucleation state synthesis of both UZM-5 and UZM-9. The overall 13C MAS NMR and IR results of this work demonstrate that UZM-5 nucleation begins with the construction of large lta-cages followed by the smaller wbc-, rth-, and d4r-cages, which is a result of the cooperation between TEA+ and TMA+. |
| 저자 |
박민범1, 전힘찬1, 조동희1, Christopher P. Nicholas2, Gregory J. Lewis2, 홍석봉1
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| 소속 |
1포항공과대, 2UOP LLC |
| 키워드 |
Zeolite; Crystallization; Charge Density Mismatch; UZM-5; UZM-9
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| E-Mail |
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| 원문파일 |
초록 보기 |
