• Resources Recycling
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• v.13 no.3
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• pp.27-36
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• 2004

Nickel oxide was recovered through roasting of a spent catalyst for hydrogenation reaction. Nickel on Kieselguhr catalysts were prepared by a precipitation method after a treatment of the recovered-nickel oxide with an acid. Effects of roasting temperature of the spent catalyst on recovery of nickel oxide was investigated. Most of nickel oxide could be recovered through roasting of the spent catalyst at $1000^{\circ}C$. In regeneration of catalysts by the precipitation method after the treatment of nickel oxide with an acid, the effect of promoter, precipitation condition and reduction condition on catalytic performance in vegetable oil hydrogenation were investigated. The addition of CaO or $Ce_2$$O_3$ resulted in an increase of catalytic activity.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.199-202
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• 2009

본 연구에서는 내부 개질반응에서 사용되는 고함량의 니켈촉매(Ni/Al2O3계열 촉매)제조를 위해, 요소(urea)를 이용한 균일용액 침전법을 이용하여 니켈이 고분산된 52wt% Ni/$Al_2O_3$ 촉매를 제조하였다. 제조 촉매는 BET 표면적, 니켈분산도, 니켈표면적 등 물리.화학적 물성 모두 우수하였으며, 환원 패턴은 상용촉매와 비슷하게 나타났다. 실제 반응온도인 $650^{\circ}C$에서 소성하여 화학흡착을 비교한 결과,상용촉매는 니켈분산도 및 니켈표면적이 감소한 반면 균일용액 침전법으로 제조한 촉매는 거의 변화가 없었다. 개질 성능 또한 상용촉매보다 우수하였는데, 이것은 균일용액 침전법으로 제조한 촉매는 활성점(니켈)이 지지체에 나노사이즈로 고르게 잘 분산되었기 때문이라고 판단하였다. 또한 합성온도 조절을 통해, $650^{\circ}C$ 소성 후에 물성변화를 살펴보았고 합성온도 $85^{\circ}C$에서 고분산 니켈 촉매 제조가 가능하였다.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.776-783
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• 2010

Co and Ni catalysts supported on $Al_2O_3$ for partial oxidation of methane producing hydrogen were synthesized using impregnation to incipient wetness. The activities of these catalysts for the partial oxidation of methane was investigated at 1 atm and $CH_4/O_2=2.0$ in the temperature range of $450{\sim}650^{\circ}C$. The reaction activity of $Ni/Al_2O_3$ and $Co/Al_2O_3$ catalysts with different loading was investigated. And the beneficial effects of Ni addition to $Co/Al_2O_3$ and the promotional effects of Ce and La addition to $Ni/Al_2O_3$ and $Co/Al_2O_3$ were investigated. These catalysts were characterized by XRD and SEM/EDX. Comparing catalyst loadings, 10 wt% Co and 10 wt% Ni were found to be optimal at the experimental conditions. The 10 wt% $Ni/Al_2O_3$ and 10 wt% $Co/Al_2O_3$ catalysts in partial oxidation of methane showed $CH_4$ conversions and CO selectivity close to the thermodynamic equilibrium levels, but showed lower $H_2$ selectivity than equilibrium level. The addition of Ni to $Co/Al_2O_3$ exhibited higher $H_2$ selectivity but beneficial effect was not observed in the $CH_4$ conversion. Addition of Ce to $Co/Al_2O_3$ and addition of La to $Ni/Al_2O_3$ a improved the $CH_4$ conversion level and $H_2$ selectivity.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.269-275
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• 2021

In this study, ordered mesoporous silica-supported Ni catalysts were prepared for catalytic partial oxidation of methane (CPOM) by using electroless nickel plating method. Unlike conventionally impregnated catalysts, the electrolessly-plated nickel catalyst showed that nickel was highly dispersed and formed stably on silica-supported surface. It was verified by TEM-EDS analysis. During the activity tests, the electrolessly-plated nickel was barely sintered and the amount of carbon deposition was very small. Consequently, the catalyst was far less deactivated, while the sintering was significantly observed in the cases of the catalysts prepared by the conventional impregnation method. Regarding the palladium-promoted catalysts, the reducibility of nickel was increased, and the reaction performances were enhanced in terms of CH4 conversion and H2/CO ratio of produced syngas.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.913-924
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• 1996

In this study HDS(hydrodesulfurization) of thiophene was researched over nickel catalysts added with small amounts of neodymium which were prepared by different methods such as unsupported coprepricipitated NdNi catalysts, unsupported intermetallic $NdNi_5$ catalysts, and carbon supported NdNi catalyst. The HDS activity was remarkably increased when a small amounts of neodymium was added to unsupported coprecipitated Ni catalysts. Thus it was known that the role of Nd is important in HDS of thiophene of Ni catalysts. For the case of unsupported intermetallic $NdNi_5$, the intermetallic crystallinity was destroyed to oxide and sulfide after calcination and presulfidation respectively. The HDS activity of thiophene can be explained by surface area of unsupported catalysts. And Nd acts like as structural promoter keeping the high surface area of unsupported catalysts. The HDS activity was increased by each ten times based on 1 gr. of nickel in the order of unsupported intermetallic $NdNi_5$, unsupported coprecipitated NdNi, and carbon supported NdNi catalysts according to different preparation method of catalysts.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.387-390
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• 2008

Ni/MgAl 촉매상에서 LPG의 수증기 개질반응을 반응온도 $700{\sim}800^{\circ}C$, 공간속도 $20,000h^{-1}$, 수증기/탄소 비율 $1.0{\sim}3.0$인 조건으로 대기압하에서 수행하였다. 본 연구에서 사용된 촉매들은 공침법으로 제조하였으며, 하이드로탈사이트 구조에서 Ni-MgO 구조로 변환되는 과정에서 활성금속인 니켈이 고분산되는 장점을 지니고 있다. 제조된 촉매는 함침법으로 제조된 촉매보다 활성이 잘 유지되었으며 탄소침적에 대한 내구성 또한 향상되었으나 완벽하게 해결되지는 못하였다. 따라서 이와 같은 문제점을 해결하기 위해 귀금속이 modified된 Ni/MgAl 촉매를 제조하고 반응 특성을 비교하였다. Rh-Ni/MgAl 촉매는 LPG 수증기 개질 반응에서 1024시간동안 활성이 유지됨을 확인하였을 뿐만 아니라 탄소침적 또한 발생하지 않음을 확인하였다.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.326-331
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• 2017

Castor oil can be used as a useful raw material for chemical industries such as intermediates of surfactants through hydrogenation reaction. In this study, effects of the preparation method and pretreatment condition on the nickel catalyst for the hydrogenation of castor oil were investigated. The nickel catalyst was supported on the silica carrier by the precipitation method with different Ni contents, solution pH values, and precipitants. Repeated pretreatments of oxidation and reduction cycles were then carried out. The activity of the nickel catalyst was measured by comparing the iodine value of the castor oil. The dispersion of nickel on the catalyst was analyzed by X-ray diffraction (XRD), $N_2$ adsorption-desorption, and transmission electron microscopy (TEM). The activity of nickel catalyst was also compared by CO oxidation experiments. The redispersion of nickel occurred on the silica by repeated oxidation and reduction cycles, and this effect contributed to promoting the castor oil hydrogenation activity.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.925-934
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• 1994

Nickel recovered from the spent oil-hydrogenation catalysts was used in hydrogenation catalyst preparation. The spent catalyst contains approximately 21.8% Ni, 0.7% Mg, and small quantities of Al, Fe, and Zn. Nickel recovery was obtained by inorganic acid digestion in the order of HCI>$NHO_3$>$H_2SO_4$. For $HNO_3$, 3hour extraction with 3N solution was satisfactory. In the PH range of 6.5~9.0, Ni recovery was higher, but metallic impurities were found to be coprecipitated. The PH in the range of 7.0~9.0 seems to be the optimum condition for separation to obtain acceptable Ni precipitates without the decrease of purity. The catalysts prepared with reclaimed nickel by wet reduction methods showed catalytic activities close to those prepared using reagent nickel in the oil hydrogenation reaction. The surface areas of the support do not seem to affect the catalytic activity.

• Clean Technology
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• v.9 no.3
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• pp.125-132
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• 2003

Activity improvement of Ni metal catalysts for carbon dioxide reforming was studied using HY-zeolite as the main supporter. As the reaction temperature increased, $CH_4$ and $CO_2$ conversions increased, and conversions higher than 80% was obtained above $700^{\circ}C$. As the Ni loading increased, the catalyst activity increased, and the highest activity was shown for the Ni loading of 13wt%. The HY-zeolite support showed the highest intial conversions of $CH_4$ and $CO_2$, but it showed faster deactivation than a ${\gamma}-Al_2O_3$ support. Nevertheless, it maintained the $CH_4$conversion higher than 80% after 24 hr reaction. The effect of promoters such as Mg, Mn, K, and Ca was also studied. It was observed that the Mg promotor exhibited the highest catalyst activity and less deactivation compared with Mn, K and Ca. After 24hr reaction, The optimum Mg content was found to be 5wt%.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.200.1-200.1
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• 2014

$TiO_2$에 니켈과 질소가 도입된 촉매를 합성하여 광촉매 활성을 연구하였다. degussa는 methylene blue 분자에 대하여 흡착능력을 거의 나타내지 않았으나, 니켈과 질소의 양이 최적화된 촉매에서는 최대 흡착량이 13.01 mg/g에 달하였다. Zeta potential 측정 결과 최대 -25.46 mV의 음전하를 나타내었으며, 각각의 촉매흡착성은 이와 비례하는 것으로 나타났다. 특히 니켈이 도입된 $TiO_2$는 흡착능력뿐만 아니라 가시광선을 이용한 MB분해 실험에서 우수한 광촉매 특성을 나타내었다.