• 제목/요약/키워드: Ga-MFI

검색결과 4건 처리시간 0.017초

갈리실리케이트(Ga-MFI)의 합성 및 ZSM-5와의 비교 (Synthesis of Gallosilicate(Ga-MFI} and Its Comparison with ZSM-5)

  • 김영국;황재영;김명수;박홍수;함현식
    • 한국응용과학기술학회지
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    • 제21권3호
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    • pp.231-237
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    • 2004
  • Ga-MFI was synthesized by a hydrothermal process at atmospheric pressure. The effect of mole ratios of reactants on crystallization was also investigated thoroughly. The characteristics of synthesized Ga-MFI was compared with ZSM-5. The synthesis of Ga-MFI was carried out with five different mole-compositions of $\underline{a}SiO_2-\underline{b}Ga_2O_3-\underline{c}Na_2O-\underline{d}TPA_2o-\underline{e}H_2O$. The synthesized Ga-MFI and ZSM-5 were characterized by XRD and FT-IR. The inorganic cation ($Na^+$) and water played an important role in crystallinity and the organic cation ($TPA^+$) as a template played a great influence on yields. With the increase in the amount of $Ga^{3+}$, crystallization time was increased. With a fixed $SiO_2/Ga_2O_3$ ratio of 400, the optimum reaction condition was obtained at $H_2O/SiO_2$=30${\sim}$35, $Na_2O/SiO_2$=0.5${\sim}$0.6, and $TPA_2O/Na_2O$=1${\sim}$1.25. In these cases, the crystallinity and yield were more than 95% and 90%, respectively. By comparing IR spectrum of Ga-MFI with those of ZSM-5 and silicalite, it was found that Ga-MFI showed a unique peak at 970 $cm^{-1}$, which may be used to identify Ga-MFI from ZSM-5 and silicalite.

Propylene Aromatization에 미치는 온도 및 촉매의 영향 (Effect of Temperature on Propylene Aromatization over MFI Type Zeolites)

  • 박진우;김상범;곽윤철;신기석;박홍수;함현식
    • 한국응용과학기술학회지
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    • 제19권2호
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    • pp.123-130
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    • 2002
  • [Ga]-MFI and H-ZSM-5 catalysts were synthesized under atmospheric pressure and used in the propylene aromatization. The effect of temperature on the product distribution was also investigated. The catalytic activities of the prepared catalysts were compared with the commercialized H-ZSM-5 which was converted from $NH_{4}$-ZSM-5. In the propylene aromatization, product distribution does not depend on the ratio of Si/$Ga_{2}$ with [Ga]-MFI catalyst, but depend on the ratio of Si/$Al_{2}$ with H-ZSM-5 catalyst [Ga]-MFI catalyst shows better dehydrogenation and alkylation activities than H-ZSM-5 catalyst The addition of Ga to H-ZSM-5 catalyst increases the conversion of propylene, selectivity to aromatics, and alkylation. In the propylene aromatization, the selectivity to aromatics slightly increased with increasing temperature with [Ga]-MFI catalyst, while slightly decreased with increasing temperature with H-ZSM-5 catalyst.

Synthesis of Ga-silicate and Its Catalytic Performance for NO Removal under the Presence of Water

  • Misook Kang;Yoon, Yong-Soo;Um, Myeong-Heon
    • Journal of Korean Society for Atmospheric Environment
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    • 제15권E호
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    • pp.1-8
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    • 1999
  • Catalytic performance for NOx removal by Ga-incorporated silicates(Ga-silicate; Gallosilicate) with MFI type synthesized by the rapid crystallization method was reported in this study. NOx removal was investigated under the condition of O2 excess(10%), with various hydrocarbons of low concentrations. Effect of H2O(2%) addition was also considered. The result showd that the conversion from NOx to N2 was enhanced on the Ga-silicate compared with the Al-silicate. Furthermore, the performance for NOx conversion on the Ga-silicate increased with addition of water.

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이산화탄소의 접촉수소화반응을 통한 탄화수소의 합성에 관한 연구 (A Study on the Synthesis of Hydrocarbon through Carbon Dioxide Hydrogenation)

  • 박영권;박광천;정광은;전종기;임선기;이동근
    • 공업화학
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    • 제8권1호
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    • pp.140-145
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    • 1997
  • $Cu/ZnO/ZrO_2$와 MFI계열의 제올라이트(HZSM-5, H-Ga-Sllicate, H-Fe-Silicate)로 이루어진 혼성촉매상에서 이산화탄소 접촉수소화반응을 수행하였다. MFI계열의 제올라이트중 브뢴스테드 산점양이 가장 많은 HZSM-5를 포함한 혼성촉매가 가장 높은 $C_2{^+}$ 탄화수소 수율을 나타내었다. HZSM-5를 포함한 혼성촉매 중에서는 $SiO_2/Al_2O_3$비가 낮을수록, 이온교환 시간이 많을수록 즉 브뢴스테드 산점의 양이 많을수록 $C_2{^+}$ 탄화수소에 대한 수율이 높았다. HZSM-5에 금속이온을 이온 교환 하였을 경우, $HZSM-5{\simeq}Ga/HZSM-5>Zn/HZSN-5$의 순서로 활성이 높았는데 이 또한 브뢴스테드 산점수가 많을수록 활성이 증가하였다.

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