• 한국수소및신에너지학회논문집
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• 제15권3호
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• pp.244-249
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• 2004

Pd catalyst have been used in hydrogenation, oxidation, and low temperature combustion reaction. Recently, it has been candidated as a possible reagents in the partial oxidation of methanol reformers of the fuel cell. Pd catalysts, even though it is very precious and expensive, catalytic functioning is good, but it still need to be improved in the matter of durability and low catalytic activity after calcination. In this study, we synthesize the improved Pd catalyst and study their chemical functioning.

• 전기화학회지
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• 제10권2호
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• pp.73-81
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• 2007

This review article considered the electrochemical reduction of uranyl ions on a Pt surface. Specifically, we focussed on the improvement in its reduction current efficiency. First, this article briefly explained the fundamentals of the reduction of uranyl ($UO_2^{2+}$) ions on a Pt surface. Namely, they involved the electrochemical behaviour of uranium species, and electrochemical cell configurations for the reduction of $UO_2^{2+}$ ions. In addition, the effects of adsorbed hydrogen atoms were investigated on the reduction of $UO_2^{2+}$ ions. Finally, this article presented the methods for improving current efficiency of the reduction of $UO_2^{2+}$ ions on a Pt surface. Three different kinds of methods are introduced, which include electrochemical surface treatments of Pt electrode involving hydrogenation and anodisation, the use of catalyst poisons, and formation of thin mercury film on a Pt electrode. Moreover, this article provided some clues about how hydrogenation and catalyst poisons work on the reduction of $UO_2^{2+}$ ions.

• 대한화학회지
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• 제32권5호
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• pp.501-506
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• 1988

본 연구에서는 알칼리화합물의 첨가가 Co/NaY촉매의 반응성과 선택도에 미치는 영향을 관찰하였다. 촉매는 제올라이트 NaY에 알칼리화합물을 첨가한 후 $Co_2(CO)_8$을 담지시켜 제조하였고, 온도 = 200∼$250^{\circ}C$, GHSV = 120∼$160hr^{-1}$, 압력 = 1atm, $H_2$/CO = 1 에서 반응하였다. 첨가된 알칼리이온의 염기도가 클수록 올레핀선택도, probability of chain growth(${\alpha}$), $CO_2$의 생성율은 증가하고 메탄의 생성율은 감소하였으며, 알칼리용액의 염기도가 클수록 반응활성은 증가하였다.

• 한국응용과학기술학회지
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• 제10권2호
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• pp.57-63
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• 1993

This study investigated the reaction and variation of fatty acid composition of soybean oil when it is partially hydrogenated until its iodine value(IV) shifts from 134 to 110. Experment was conducted under he outlined reactiion conditions of temperatures(170, 190 and $210^{\circ}C$), pressure(1.3, 2.8 and 4.2atm) and nickel(Ni) catalyst concentraons(0.005, 0.01, 0.05, and 0.1%) with a fixed agitation(350rpm). Further investigation was also made to see the effect of added lecithin on hydrogenation. When reaction temperature was gradually raised and catalyst concentration increased, the content of linolenic acid progressively decreased while the increase amount of stearic acid reduced(P<0.05). On he other hand when pressure gradually increased, the contents of stearic acid and linolenic acid increased(P<0.05). Meanwhile when lecithin was added, reaction time increased by two to six times more than when no addition was made.

• 공업화학
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• 제26권5호
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• pp.575-580
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• 2015

본 연구는 여러 가지 방법에 의해 제조된 Pd/C 촉매의 특성을 질소흡탈착등온선, XRD, FE-TEM 및 CO-chemisorption을 이용하여 확인하였고, 제조된 촉매의 활성을 cyclohexene의 수소화 반응을 통하여 확인하여 제조방법에 따른 촉매의 특성 변화가 촉매 활성에 미치는 영향에 대하여 연구하였다. 각각의 제조방법을 통하여 제조된 Pd/C 촉매의 FE-TEM 분석결과, 이온교환법으로 제조된 촉매의 분산 정도가 매우 우수하며, 폴리올법으로 제조된 촉매의 분산 정도가 매우 낮음을 확인하였다. CO-chemisorption 분석에 의한 분산도 결과 이온교환법, 함침법 및 폴리올법으로 제조된 촉매의 Pd 분산도가 각각 17.55, 13.82% 및 1.35%로 나타나 FE-TEM 결과와 일치함을 확인하였다. 이후 cyclohexene의 수소화반응을 통하여 제조된 촉매의 활성을 확인하였고, 이온교환법으로 제조된 촉매의 cyclohexene의 전환율이 71%로 가장 높음을 확인하였다. 이는 탄소 담지체에 담지된 Pd의 분산도가 반응 활성에 영향을 미쳐 나타난 결과임을 알 수 있었다.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.168-174
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• 2023

일반적인 메틸 메타아크릴레이트(methyl methacrylate) 상업 공정의 중간체인 메타아크릴 알데히드(methacryl aldehyde)에는 불순물이 존재한다. 이는 전체 화학 반응의 전환율과 선택도가 크게 저하되는 원인이며 메타아릴 알코올(methallyl alcohol) 생산성 향상의 주요 문제이다. 본 연구는 다양한 불순물 중에서 반응성 저하의 주요 원인이 산(acid)임을 발견하였다. 불순물로 존재하는 산은 촉매의 활성을 급격하게 저하시키며, 부반응인 불균일 딜스-알더 반응(hetero Diels-Alder reaction)이 촉진됨을 확인하였다. 따라서, 메타아크릴 알데히드의 카르보닐기(carbonyl group)를 선택적으로 수소화하는 반응에서 반응 불순물인 산을 제거하기 위해 전처리 방법을 비교 평가하였고, 생산성을 향상시키기 위한 효과적인 방법을 제안하였다. 이를 통해 제안된 조건 하에서 최적의 선택적 수소화 반응 조건을 완성하였다.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.415-423
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• 2011

HI decomposition step certainly demand catalytic reaction for efficient production of hydrogen in SI process. Platinum catalyst can apply to HI decomposition reaction as well as hydrogenation or dehydrogenation. Generally, noble metal is used as catalyst which is loaded form for getting high dispersion and wide active area. In this study, Pt was loaded onto zirconia, ceria, alumina, and silica by impregnation method. HI decomposition reaction was carried out under the condition of $450^{\circ}C$, 1atm, and $167.76h^{-1}$ (WHSV) in a fixed bed reactor for measuring catalytic activity. And property of a catalyst was observed by BET, TEM, XRD and chemisoption analysis. On the basis of experimental results, we discussed about conversion of HI according to physical properties of the loaded Pt catalyst onto each support.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2726-2732
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• 2014

The promoting effect of rhodium on the structure and activity of the supported Cu-Co based catalysts for CO hydrogenation was investigated in detail. The samples were characterized by DRIFTS, $N_2$-adsorption, XRD, $H_2$-TPR, $H_2$-TPD and XPS. The results indicated that the introduction of rhodium to Cu-Co catalysts resulted in modification of metal dispersion, reducibility and crystal structure. DRIFTS results of CO hydrogenation at reaction condition (P=2 MPa, $T=260^{\circ}C$) indicated the addition of 1 wt % rhodium improved hydrogenation ability of Cu-Co catalysts. The ethanol selectivity and CO conversion were both improved by 1 wt % Rh promoted Cu-Co based catalysts. The alcohol distribution over un-promoted and rhodium promoted Cu-Co based catalysts obeys A-S-F rule and higher chain growth probability was got on rhodium promoted catalyst.

• 청정기술
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• 제30권2호
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• pp.145-156
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• 2024

탄소는 비표면적이 매우 크고 우수한 화학적 안정성을 지녀 촉매 지지체로 사용한 연구들이 활발히 진행되고 있다. 탄소를 지지체로 사용하는데 있어 전처리 과정은 필수적이다. 전처리를 통해 금속 입자의 성장을 제어해 안정화하고 지지체와 금속 입자 간 결합력을 향상시킬 수 있다. 본 연구에서는 표면 개질을 위해 탄소의 전처리를 실시하였으며 이를 촉매 지지체로 사용해 5 wt% Pd/C 촉매를 합성하였다. 제조된 촉매의 활성은 페놀 수소화 반응을 통해 평가되었다. 탄소 전처리 시 일반적으로 사용되는 질산과 비교하고자 유기산을 사용해 탄소 전처리를 진행하였고 이를 지지체로 사용해 촉매를 제조하였다. 글루콘산으로 처리된 촉매는 94.93%의 전환율과 92.76%의 사이클로헥사논 선택도를 나타내 질산으로 처리된 촉매보다 우수한 활성을 나타냈다. 따라서 유기산을 이용한 탄소의 전처리가 무기산 처리의 단점을 개선하는 것뿐만 아니라 촉매 성능 개선에 도움을 줄 수 있을 것으로 기대된다.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.110-117
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• 2015

10 wt% (Ni-Co) catalysts with different Ni and Co content : 10%Ni, 9%Ni1%Co, 7%Ni3%Co, 5%Ni5%Co, 3%Ni7%Co, and 10%Co; were prepared using sol-gel method followed by incipient wetness impregnation method. To investigate the catalytic activity including the stability, dry methane reforming were demonstrated over the pelletized catalysts at $620^{\circ}C$ under atmospheric pressure in a $CH_4:CO_2:N_2$ feedstock for 360 min. The results showed that bimetallic catalysts with the Co content equal to or greater than 3% were more stable than monometallic catalysts (10%Ni and 10%Co). The temperature programmed hydrogenation interpreted that the additional of Co into Ni catalyst improved the carbon resistance from methane cracking. Promoted this type of bimetallic catalyst using 1wt% K (trimetallic catalyst) prevented the carbon formation on the catalyst. The temperature programmed desorption of $CO_2$ indicated that this trimetallic catalyst has a greater number of strong basic sites. Moreover, the appearance of K lowered the number of weak basic sites and decreased the conversion of methane by 12 %.