• Bulletin of the Korean Chemical Society
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• 제19권12호
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• pp.1342-1346
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• 1998

The dehydrogenation of ethylbenzene with carbon dioxide has been carried out over ZSM-5 zeolite-supported iron oxide catalyst as well as commercial catalyst (K-Fe2O3) and unsupported iron oxide (Fe3O4) for comparison. In the dehydrogenation over the ZSM-5 zeolite-supported iron oxide catalyst, ethylbenzene is predominantly converted to styrene by an oxidative pathway in the presence of excess carbon dioxide. Carbon dioxide in this reaction is found to play a role as an oxidant for promoting catalytic activity as well as coke resistance of catalyst. On the other hand, both of commercial catalyst and unsupported Fe2O4 exhibit considerable decrease in catalytic activity under the same condition. It is suggested that an active phase for the dehydrogenation with carbon dioxide over ZSM-5 zeolite-supported iron oxide catalyst would be rather a reduced and isolated magnetite (Fe3O4)-like phase having oxygen deficiency in the zeolite matrix.

• 자원리싸이클링
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• 제30권2호
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• pp.68-74
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• 2021

본 연구에서는 촉매 Co-ZSM5 및 Cu-ZSM5 코팅이 적용된 저품위 실리카를 사용하여 다공성 지지체를 제조하여 포름 알데히드(HCHO) 제거를 수행하였다. 먼저, 지지체 원료는 실리카가 90 % 함유되어 있어 저급 실리카로 확인되었다. EDS 및 FT-IR 분석에 따르면 Co-ZSM5 및 Cu-ZSM5 촉매는 다공성 실리카 지지체의 표면에 성공적으로 코팅되었다. 제조 된 Co-ZSM5 및 Cu-ZSM5 코팅 된 비드를 사용하여 HCHO의 제거 테스트 결과, 반응 온도에 따라 Co-ZSM5 코팅 된 비드는 Cu-ZSM5 비드보다 높은 제거 효율 (> 97 %)을 나타났다. 200 ℃. 전자의 더 높은 효율은 우수한 표면 활성 특성 (BET 표면적 및 기공 부피)에서 기인 할 수 있으며, 아마도 유리한 HCHO 분해로 이어질 수 있다. 따라서 Co-ZSM5 비드는 국산 저급 실리카를 사용하여 제작 된 다공성 지지체를 사용하여 HCHO 제거 용 촉매에 적합한 것으로 판단된다.

• 청정기술
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• 제18권1호
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• pp.89-94
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• 2012

본 연구에서는 산성을 갖는 Fe-ZSM5를 담체로 활용하여 Pd, Pt 등 귀금속을 담지한 후, 제조 촉매의 암모니아의 선택적 산화반응 활성을 평가하였다. 이들 중 Pt/Fe-ZSM5가 Pd/Fe-ZSM5 보다 높은 활성을 나타냈다. 또한 Pt/Fe-ZSM5 촉매에서 ZSM5 구조체 내 Fe의 이온교환량을 달리한 촉매의 실험을 수행하여, 암모니아의 선택적 산화반응에 가장 우수한 활성을 보이는 최적 조성비를 탐색하였다. 그 결과, Fe의 이온교환량이 적을수록 반응 활성이 증가하는 경향을 보였고, 저온 영역인 $250^{\circ}C$에서 100%의 암모니아 전환율을 나타냈다. 이와 같이 암모니아의 선택적 산화반응에 효과적인 Fe-ZSM5 담체에 대하여, ICP-AES, BET, XRD, $NH_3$-TPD 등과 같은 특성 분석을 수행하여 제조 촉매의 구조와 물성이 반응활성에 미치는 영향을 검토해보았다.

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.681-686
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• 2004

Ti-ZSM-5 prepared by secondary synthesis, from the reaction of H-ZSM-5 with vapor phase $TiCl_4$, was characterized with several physicochemical techniques including FT-IR and UV/VIS-DRS. It was found that zeolite structure, surface area and pore volume did not change, and the framework aluminum could not be replaced by titanium atom during the secondary synthesis of Ti-ZSM-5. The incorporation of titanium into the framework might be due to reaction of $TiCl_4$with the silanol groups associated with defects or surface sites. The formation of extra-framework titanium could not be avoided, unless the samples were further treated by water vapor at 550 $^{\circ}C$ or higher temperature. High temperature steam treatment of Ti-ZSM-5 prepared by chemical vapor deposition with $TiCl_4$was efficient to prevent the formation of non-framework titanium species. Ti-ZSM-5 zeolites prepared in this work contained only framework titanium species and exhibited improved catalytic property close to TS-1 prepared by hydrothermal synthesis.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.60-67
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• 2008

The catalytic filter of Cu-ZSM5/alumina beads was considered to reduce NOx in the urea SCR system. Catalytic support of porous alumina beads with mean pore size $130{\mu}m$ and porosity $75{\sim}83%$ were prepared using foaming and gel-casting method. The Cu-ZSM5 catalysts were coated on the supporting alumina beads using $Cu(NO_3)_2$ by ion exchange method. After a washcoating process was applied to coat 10w% Cu-ZSM5 on porous alumina bead, coating layer was estimated $20{\mu}m$ in thickness. The characterization and the feasibility as a catalytic supports were investigated. And the NOx conversion test in Cu-ZSM5/Alumina Beads filter system was conducted by using Urea as reductants under laboratory test. The NOx conversion was increased as size and porosity of beads and observed more than 95% excellent NOx conversion above $300^{\circ}C$.

• 대한환경공학회지
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• 제28권9호
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• pp.955-960
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• 2006

반회분식 반응기를 이용하여, 폐 고밀도 폴리에틸렌(HDPE)으로부터 가솔린을 제조하기 위하여 HZSM-5 촉매상에서 분해반응을 수행하였다. HZSM-5 촉매상에서 가솔린 분자 범위의 액상수율을 증가시키기 위하여 시판용의 Si/ZSM-5 촉매와, 인과 마그네슘을 HZSM-5 촉매에 첨가한 촉매를 사용하여 접촉분해반응 특성을 조사하였다. HZSM-5에 인과 마그네슘을 지지한 경우, 최적 지지량은 각각 0.5 wt%와 2.0 wt%이었다. 암모니아 TPD 실험 결과에서 인을 지지 시켰을 때는 강산점과 약산점이 전체적으로 크게 감소하였으며, 마그네슘을 지지 시켰을 때는 강산점은 완만하게 감소하였고 약산점은 크게 감소하였다. Si/ZSM-5 촉매에서는 산점은 거의 사라졌으며 분해반응도 크게 감소하여 액상생성물이 거의 생성되지 않았다. 액상생성물의 탄소수 분포는 인과 마그네슘이 지지되었을 때 탄소수가 낮은 쪽으로 이동되었고 성분의 100%가 가솔린 범위($C_5-C_{11}$)에 분포되어 있었다. Mg(2.0 wt%)/ZSM-5 촉매는 반응온도 $400^{\circ}C$E에서 액상 수율이 55.8%이었으며, 생성물의 분포가 100% 가솔린 범위에 있어서 유망한 촉매로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3059-3064
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• 2013

In this study transesterification of Triglycerides (TG) from Jatropha curcas oil (JCO) with methanol for production of biodiesel was investigated over cerium impregnated ZSM-5 catalysts. NaZSM-5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as a source for cerium. They were characterized by X-ray diffraction (XRD), Thermogravimeteric analysis (TGA), $CO_2$-temperature programmed desorption, and $N_2$ adsorption/desorption analysis. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is an evident for 10 and 15% loading. The optimal yield of transesterification process was found to be 90% under the following conditions: oil to methanol molar ratio: 1:12; temperature: $60^{\circ}C$; time: 1 h; catalyst: 5 wt %. Here the yield of fatty acid methyl ester (FAME) was calculated through $^1H$ NMR analysis. The investigation on catalyst loading, temperature, time and reusability illustrated that these ceria impregnated NaZSM-5's were found to be selective, recyclable and could yield biodiesel at low temperature with low methanol to oil ratio due to the presence of both Lewis and Bronsted basicity. Hence, from the above study it is concluded that ceria impregnated ZSM-5 could be recognized as a potential catalysts for biodiesel production in industrial processes.

• 한국응용과학기술학회지
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• 제17권1호
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• pp.1-5
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• 2000

The selective catalytic reduction(SCR) of nitric oxide by ethane in the presence of oxygen was investigated on Cu-ZSM-5, Co-ZSM-5 and Ga-ZSM-5 catalysts over a range of 400, 450 and $500^{\circ}C$. The catalysts were prepared by ion-exchange method. The composition of the reactant gases were 1000 ppm of NO, 1000 ppm of $C_{2}H_{6}$ and 2.5% of $O_{2}$, and the reaction was conducted in a fixed-bed reactor at 1 atm. For the 20wt% Co-ZSM-5(50) catalyst, the NO conversion reached up to 100%, while the $C_2H_6$ conversion and the CO selectivity were about 50% and 25%, respectively, at $450^{\circ}C$. For the 20wt% Cu-ZSM-5(50) catalyst, the NO conversion and the C2H6 conversion were about 80% and 100%, respectively, but there was no CO produced. The metal ion-exchanged ZSM-5 catalysts exhibited a tendency to increase the NO conversion with the Si/Al ratio of the ZSM-5, that is, NO conversion was inversely proportional to the acidity of the catalysts. But, the effect of the acidity on NO conversion was not so large. From the XRD results of the catalysts before and after SCR reaction it was found that there was no structural change.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.118-118
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• 1996

• 공업화학
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• 제5권6호
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• pp.957-966
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• 1994

HZSM-5와 Ag 이온으로 교환된 ZSM-5를 촉매로 사용하여 부탄과 1-부텐으로부터 방향족 화합물로의 전환반응을 수행하였다. 방향족 탄화수소의 수율은 HZSM-5 내에 Ag 이온을 도입함으로써 현저하게 증가하였다 Ag 이온들은 출발원료인 탄화수소의 탈수소 촉매로서 작용하였다. 부탄과 1-부텐의 탈수소 과정에서 생성된 수소는 $Ag^+$ 이온을 Ag 금속으로 환원시킴과 동시에 산점의 형성을 유발하였다. Ag의 담지량이 다른 ZSM-5를 촉매로 사용하여 1-부텐의 전환반응을 수행하고, 이들 촉매의 산점특성 변화에 따른 효과를 검토하였다.