• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.57-59
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• 2001

• 한국표면공학회지
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• 제22권2호
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• pp.69-77
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• 1989

Codeposion of inert particles particles in a metallic mateix by electroless plating process involves two phenomena. Firstly, the adsorption of inercles and secondly, the adsorption of inert particles on the cathode. In the present paper the first adsorption phenomenon and in the next paper the second ane are studied in greaterdetail for the Ni-SiCc, Ni-Al2AO3 and Ni-WC systems. Measurements of the Zeta potentials for the SiC and Al2AO3 particles have been in different electrolyte solutions and the ionic species adsorbed on the Particles studied. The addition of sodium acetate, trisodium citrate and sodium phosphinate to nikel sulface sruomotes the zeta potential of SiC and Al2O3 particles, but zeta phosphinate to nickel is more positive than Al2O3 particles although the amount of nickel ion adsorbrd on the Al2O3 particles become greater than that of SiC particles. It is suggested that this is due to adsortion of Na ion onto the surface SiC particles.

• 한국세라믹학회지
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• 제51권5호
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• pp.477-480
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• 2014

An $Al_2O_3$-CuO-ZnO (ACZ) precursor powder was synthesized by a facial sol-gel process using a nonionic surfactant span 80 as the chelating agent to improve the surface area and morphology. When creating a hydrogen membrane, several kinds of properties are required, such as easy dissociation of hydrogen molecules, fast hydrogen diffusion, high hydrogen solubility, and resistance to hydrogen embrittlement. ACZ-Ni composite membranes (cermet) were prepared with this precursor and pure Ni powder via the hot press sintering (HPS) method. The ACZ powder was characterized by XRD, BET, and FE-SEM. Hydrogen permeation experiments were performed by Sievert's type of hydrogen permeation membrane equipment. The hydrogen permeability of ACZ/Ni 10 wt% and ACZ/Ni 20 wt% was obtained as 7.2 and $10molm^{-2}s^{-1}$ at RT, respectively. These values of the corresponding membranes were slightly increased with increasing pressures.

• 한국세라믹학회지
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• 제40권6호
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• pp.560-565
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• 2003

방전 플라즈마 소결법(SPS: Spark Plasma Sintering)을 이용하여 800~100$0^{\circ}C$의 낮은 소결 온도에서 완전 치밀화를 이루는 M-doped ZnO를 (M=Al, Ni) 제조하여 그 소결 특성과 미세구조를 분석하였다. 전자현미경 분석 결과, NiO의 첨가는 ZnO 결정격자와의 고용체 형성을 촉진시키고 결정립 성장을 유발하였고, A1$_2$O$_3$는 순수한 ZnO 소결 시 나타나는 입계에서의 증발현상을 제어하고, 이차상 형성을 통하여 결정립 성장을 억제함을 확인할 수 있었다 NiO와 $Al_2$O$_3$를 동시에 첨가한 시편이 가장 우수한 미세구조가 형성됨을 확인하였고, SEM-EBSP (Electron Back-scattered Diffraction Pattern) 분석 결과 또한 우수한 결정립계 분포를 가지고 있음을 확인하였다. 이러한, 소결체의 우수한 미세구조적 특징은 carrier 농도 증가에 따른 전기 전도도와 증가 및 phonon scattering 효과에 의한 열전도도의 감소 효과를 유발하여 ZnO의 열전 특성을 향상시키리라 사료된다.

• 한국표면공학회지
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• 제43권4호
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• pp.165-169
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• 2010

$Ni-Al_2O_3$ nanocomposite coatings were fabricated by conventional electrodeposition technique using nickel sulfamate bath. Effect of plating parameters on electrodeposition of $Ni-Al_2O_3$ nanocomposite were studied. The properties of the nano composite were investigated by using SEM, XRD, and Vicker's microhardness test. The results demonstrated that $Al_2O_3$ incorporation in the composite coatings was found to be increased by increasing stir rate and $Al_2O_3$ content in plating bath. Microhardness of the composite coatings was also increased with increasing content of the nano particles in the plating bath. The surface morphologies of the nanocomposite coatings were found to be varied with varying pH, current densities as well as alumina content in the plating bath.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.256-259
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• 2005

본 연구에서는 기존 니켈 활성성분만의 알루미나담지 촉매에 비해 고온에서의 수소를 사용한 환원 전처리 과정을 거치지 않고도 높은 반응활성을 나타내며, 반응 중 탄소침적에 대한 촉매 저항성에서도 우수한 결과를 나타낸 루테늄-니켈 촉매에 대해보고 하고자 한다. 메탄 수증기 개질 반응을 통해, 루테늄을 최종적으로 담지한 알루미나 담지니켈계 촉매는 별도의 전처리과정 없이 $650^{\circ}C$에서부터 높은 반응성을 보였으며, 루테늄과 니켈을 동시에 담지한 경우보다 더 우수한 활성을 나타내었다. Ru의 담지량을 달리한 실험에서는$RU(0.5)/Ni(20)/Al_2O_3$ 촉매가 가장 높은 활성을 보였다. $H_2-TPR$ 분석 결과, $Ru(0.5)/Ni(20)/A1_2O_3$촉매의 경우 세 가지 환원 피크가 나타났으며, $Ni(20)/A1_2O_3$촉매와 비교해 볼 때, 저온(<$130^{\circ}C)$에서 환원가능한 $RUO_2$의 존재를 확인할 수 있었다. 담지된 RU은 분산도가 높아, XRD분석 결과에서 Ru이나 $RuO_2$의 특성 피크가 존재하지 않았다. 또한 $650^{\circ}C$에서 10시간 개질반응 후 얻어진 촉매에 대해 $O_2-TGA$를 분석한 결과, $Ni(20)/Al_2O_3$촉매는 $-7.2wt\%$ 정도의 큰 무게 감소를 보였으며, 이는 촉매 표면에 생성된 carbon tube에 의한 것임을 SEM 분석을 통해 알 수 있었다 이에 반해, $Ru(0.5)/Ni(20)/Al_2O_$ 촉매는 $O_2-TGA$시 $0.3wt\%$ 정도 무게 증가에 그쳤으며, SEM 분석상 carbon tube의 생성이 크게 억제되었음을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제22권2호
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• pp.164-170
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• 2001

The crystal structures of fully dehydrated Ni2+- and Tl+ -exchanged zeolite X (Ni17Tl58-X, and Ni12Tl68-X; X=Si100Al92O384) have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at $21(1)^{\circ}C$ (a=24.380(4) $\AA$, 24.660(4) $\AA$, respectively). Their structures have been refined to the final error indices R1=0.037 and R2=0.043 with 485 reflections, and R1=0.039 and R2=0.040 with 306 reflections, respectively, for which I >36(I). In Ni17Tl58-X, 17 Ni2+ ions per unit cell were found at only two sites: 15 at site I at the center of the hexagonal prism (Ni-O=2.203(9) $\AA)$ and the remaining 2 at site II near single six-oxygen rings in the supercage (Ni-O=2.16(3) $\AA).$ Fifty-eight Tl+ ions were found at five crystallographic sites: 28 at site II (Tl-O=2.626(8) $\AA)$, 2 at site I' in the sodalite cavity near the hexagonal prism (Tl-O=2.85(1) $\AA)$, another 2 at site II' in the sodalite cavity (Tl-O=2.77(1) $\AA).$ The remaining 26 were found at two nonequivalent Ⅲ' sites with occupancies of 23 and 3. In Ni12Tl68-X, 12 Ni2+ ions per unit cell were found at two sites: 10 at site I (Ni-O=2.37(2) $\AA)$ and the remaining 2 at site II (Ni-O=2.13(2) $\AA).$ Sixty-eight Tl+ ions were found at five crystallographic sites: 28 at site II (Tl-O=2.63(1) $\AA)$, 12 at site I' (Tl-O=2.62(1) $\AA)$, 2 at site II' (Tl-O=3.01(2) $\AA)$, and the remaining 26 at two III' sites with occupancies of 23 and 3. It appears that Ni 2+ ions prefer to occupy site I and II, in that order. The large Tl+ ions occupy the remaining sites, I', II, II' and two different III' sites. In both crystals, only the Ni2+ ions at site II were reduced and migrated to the external surface of zeolite X when these crystals were treated with hydrogen gas.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3205-3208
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• 2014

Catalytic gasification of cellulose was carried out in a U-type fixed reactor with Ni loaded MSU-F catalyst (Ni/MSU-F) and Ni loaded ${\gamma}-Al_2O_3$ (Ni/${\gamma}-Al_2O_3$). The characteristics of the catalysts were analyzed by using X-ray diffraction, $H_2$-temperature programmed reduction, and Brunauer-Emmett-Teller analyses. The operation conditions of catalytic gasification reactions were $750^{\circ}$ and 0.2 equivalence ratio. Air was used as gasification agent. Catalytic gasification characteristics, such as gas yield and gas composition ($H_2$, CO, $CO_2$, $C_1-C_4$), were measured and calculated. The gas yield of Ni/MSU-F was much higher than that of Ni/${\gamma}-Al_2O_3$. Especially high amount of hydrogen was produced by Ni/MSU-F.

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.232-238
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• 2021

The development of a low cost catalyst with high performance and small amount of carbon deposition on catalyst from toluene steam reforming were investigated by using coal ash as a support material. Ni-loaded coal ash catalyst showed similar catalytic activity for toluene steam reforming compared with the Ni/Al2O3. At 800 ℃, the toluene conversion was 77% for Ni/TAL, 68% for Ni/KPU and 78% for Ni/Al2O3. Ni/TAL showed similar toluene conversion to Ni/Al2O3. However, Ni/KPU produced higher hydrogen yield at relatively lower toluene conversion. Ni/KPU catalyst showed a remarkable ability of suppressing the carbon deposition. The difference in coke deposition and hydrogen yield is due to the composition of KPU ash (Ca and Fe) which increase coke resistance and water gas shift reaction. This study suggests that coal ash catalysts have great potential for the application in the steam reforming of biomass tar.

• 한국세라믹학회지
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• 제43권5호
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• pp.265-269
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• 2006

We have deposited NiO films by RF sputtering on $Al_2O_3/SiO_2/Si$ and 100 nm-thick Gd doped $CeO_2$ covered $Al_2O_3/SiO_2/Si$ substrates at various $Ar/O_2$ ratios. The deposited films were reduced to form porous Ni thin fllms in 4% $H_2\;at\;400^{\circ}C$. For the films deposited in pure Ar, the reduction was retarded due to the thickness and the orientation of the NiO films. On the other hand, the films deposited in oxygen mixed ambient were reduced and formed porous Ni films after 20 min of reduction. We also investigated the possibility of using the films for the single chamber operation by studying the electrical property of the films in the fuel/air mixed environment. It is shown that the resistance of the Ni film increases quickly in the mixed gas environment and thus further improvements of Ni-base anodes are required for using them in the single chamber operation.