철과 코발트 산화물의 수소 환원에 니켈 및 팔라듐 첨가의 효과

김종팔 한국수소및신에너지학회 2011 한국수소 및 신에너지학회논문집 Vol.22 No.1

Temperature programmed reduction experiments for Fe- and Co-oxides were performed and weight losses were carefully measured to calculate the extent of reduction. Addition of nickel and palladium affected the reduction by lowering the DTG peak temperature. Reduction experiments for the oxides on alumina were also studied and the effect of nickel and palladium addition was confirmed. And that was explained by means of increased adsorption of hydrogen and increased diffusion ability of the surface hydrogen.

철 산화물과 지지체 표면의 철 산화물의 환원에 니케로가 팔라듐 첨가의 효과

김종팔,이광현 동의대학교 산업기술개발연구소 2007 産業技術硏究誌 Vol.21 No.-

Rochow 공정에서 반응 경로 연구

김종팔 東義大學校産業技術開發硏究所 2011 産業技術硏究誌 Vol.25 No.-

구리 촉매를 이용하여 기체상태의 silanes 을 실리콘으로부터 직접 생성하는 공정이 Rochow 에 의해 제시되었고 이에 따라 silanes 생성에 관한 많은 연구가 진행되어 오고 있다. 본 연구에서는 실리콘 표면에 존재 하는 것으로 보고된 실리콘 활성점인 =SiCl2 와 =Si(CH3)Cl 에서 methylchloride(CH3Cl) 의 해리흡착에 따른 메틸그룹의 활성점 내 흡착과 역시 해리 흡착한 후 표면에 존재하여 표면 이동을 하는 것으로 간주되는 Cl 와 H 을 이용하여 생성되는 각 silanes 의 생성 경로를 제시하였다. 제시된 각 silanes 들의 생성 경로는 앞서 수행한 반응 과정 중 생성된 silanes 의 종류 와 함께 TPD 과정에서 생성되는 각 silanes 종류들의 생성 과정을 명확히 설명해 주고 있다. 더구나 silanes 직접 생산에서 사용되는 촉매인 구리 외에 활성 및 선택성을 높여 주는 것으로 알려진 아연과 주석의 역할까지 효과적으로 설명해주고 있다. Reaction pathes were proposed using dissociative adsorption of methylchloride and surface diffusion of surface Cl and H. The active silicon sites were considerred as =SlCl2 and =Sl(CH3)Cl. The synthesis path of many types of methylchlorosilanes were explained by the adsorption of methyl group on the silicon sites and the surface diffusion of nearby Cl and H to the silicon sites. And it also explained the silanes formed not only during reaction but also during TPD process. The proposed reaction path further explained the formation of many silanes with the role of catalyst (Cu) and promoters (Zn and Sn).

큰 입력 신호 범위를 위한 바이오 임피던스 측정 회로

김종팔 대한전자공학회 2022 전자공학회논문지 Vol.59 No.4

바이오임피던스 측정을 위한 새로운 방식의 집적회로를 설계하였으며 시뮬레이션을 통하여 검증하였다. 바이오임피던스의 특징으로 통상 임피던스 수준의 1% 미만의 임피던스 변화를 측정하여야 한다. 이는 인가 전류에 의해 유기되는 전압 신호가 측정하고자 하는 임피던스 변화에 의한 전압 변동분에 비해 매우 큰 특징을 가진다. 이 때문에 측정회로에서 측정 신호 증폭시 포화되는 것을 회피하기 위하여 기본적으로 고 증폭이득을 활용하지 못하였다. 일반적으로 1.8 V 동작전압 사용시 30 mV 입력신호에 대하여 최대 증폭이득은 60 V/V가 한계이지만, 본 논문에서는 이를 극복할 수 있는 신호접기 방식을 제안하였으며 포화현상 없이 390배 증폭이 가능함을 보였다.

ORTHO/PARA 수소의 전환에의 연구

김종팔,이광현 한국수소및신에너지학회 2007 한국수소 및 신에너지학회논문집 Vol.18 No.3

The conversion reaction of ortho to para hydrogen was studied. The percentage of ortho and para hydrogen is mainly dependent on the equilibrium temperature. Because this reaction is known to be accelerated by the catalyst such as nickel-silicate and ruthenium on silica, we focused in the test and development of the catalysts. We studied metal-silicates because they provide high metal dispersion on support. Nickel-silicate, ruthenium-silicate and mixed-silicate were prepared by the coprecipitation method and used in the reaction at the temperature of liquid nitrogen. The conversion was measured by the difference of thermal conductivity between reference gas and sample gas. The activation condition was important and it affected the activities of the catalysts. Nickel-silicate showed high activities. Ruthenium-silicate also showed relative high activities but mixed-silicate showed poor activities.

목장 발전을 위한 자가수정과 기록방법

김종팔 한국낙농육우협회 1994 낙농·육우 Vol.14 No.10

Effect of Palladium and Nickel on the Temperature Programmed Reduction of Metal Oxides and Metal Oxide Layers

김종팔 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

A new binary oxide support was suggested as being useful in many commercial reactions. Our study wasfocused on the reduction effect of metal oxide layer on alumina during reaction. Hence temperature programmedreduction of both bulk metal oxide and metal oxide layer on alumina was studied first and the effect of palladium andnickel on the reduction of the oxide support was also investigated. Vanadium oxide was mainly studied and niobiumoxide, tantalum oxide, titanium oxide and zirconium oxide were also compared. Some metal oxides were reduced ina hydrogen stream at elevated temperature. In these cases both the bulk metal oxide and metal oxide layer werereduced. A tiny amount of palladium or nickel afected the reduction by decreasing the reduction temperature. Thedecrease of the reduction temperature was explained by means of increased adsorption of hydrogen on the transitionmetal and ability of the metal to spillover of the hydrogen to the oxides.

표면미세가공기술을 이용한 수평감지방식의 정전용량형 다결정 실리콘 가속도계의 설계, 제작 및 가공 오차 영향 분석

김종팔,한기호,조영호,Kim, Jong-Pal,Han, Gi-Ho,Jo, Yeong-Ho 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.3

We investigate a surface-micromachined capacitive accelerometer with the grid-type electrodes surrounded by a perforated proof-mass frame. An electromechanical analysis of the microaccelerometer has been performed to obtain analytical formulae for natural frequency and output sensitivity response estimation. A set of prototype devices has been designed and fabricated based on a 4-mask surface-micromachining process. The resonant frequency of 5.8$\pm$0.17kHz and the detection sensitivity of 0.28$\pm$0.03mV/g have been measured from the fabricated devices. The parasitic capacitance of the detection circuit with a charge amplifier has been measured as 3.34$\pm$1.16pF. From the uncertainty analysis, we find that the major uncertainty in the natural frequency of the accelerometer comes from the micromachining error in the beam width patterning process. The major source of the sensitivity uncertainty includes uncertainty of the parasitic capacitance, the inter-electrode gap and the resonant frequency, contributing to the overall sensitivity uncertainty in the portions of 75%, 14% and 11%, respectively.

코발트 산화물과 지지체 표면의 코발트 산화물의 환원에 니켈과 팔라듐 첨가의 효과

김종팔,이광현 동의대학교 산업기술개발연구소 2006 産業技術硏究誌 Vol.20 No.-

A binary oxide support was suggested as being useful in many commercial reactions. This study was focused on the reduction effect of metal oxide on alumina surface. Hence temperature programmed reduction of both bulk metal oxide and metal oxide on alumina surface was studied first and effect of nickel and palladium on the reduction of the metal oxides was also investigated. Cobalt oxide was studied and it was reduced in a hydrogen stream at elevated temperature. In these cases both the bulk metal oxide and metal oxide on surface were reduced. A tiny amount of palladium or nickel affected the reduction by decreasing the reduction temperature. The decrease of the reduction temperature was explained by means of increased adsorption of hydrogen on the transition metal and ability of the metal to spillover of the hydrogen to the oxides.

다공성 금속 촉매를 이용한 메틸사이클로헥산의 탈수소 반응

김종팔 한국수소및신에너지학회 2004 한국수소 및 신에너지학회논문집 Vol.15 No.2

Hydrogen has been considered as an important and essential future energy source. But the storage of the hydrogen is a difficult problem and many studies were focused on this matter. However, the MTH-system (methylcyclohexane, toluene, hydrogen) was proposed for storage of hydrogen by Taube et al. and that is the reaction of hydrogen with toluene to give methylcyclohexane. One toluene molecule can store six hydrogen atoms to form methylcyclohexane. In this form the hydrogen can be easily stored in liquid organic hydrides and transported at ambient pressure in tanks. Hence, this study is focused on the catalytic dehydrogenation of methylcyclohexane. Since supported platinum and nickel were employed as catalysts in literature, in this study, porous Pt and Ni were prepared and tested for the dehydrogenation reaction. When the porous Pt catalyst was applied to the dehydrogenation it showed higher activity in the reaction and higher selectivity to toluene. Specially at higher pressure, it showed almost 100 % conversion and 100 % selectivity and hence porous platinum could be considered as best for the given reaction.