• 한국표면공학회지
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• 제56권6호
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• pp.427-436
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• 2023

In the industry, it is recognized that human activities significantly lead to a large amount of wastewater, mainly due to the increased use of water and energy. As a result, the growing field of wastewater resource technology is getting more attention. The common technology for hydrogen production, water electrolysis, requires purified water, leading to the need for desalination and reprocessing. However, producing hydrogen directly from wastewater could be a more cost-effective option compared to traditional methods. To achieve this, a series of first-principle computational simulations were conducted to assess how waste nutrient ions affect standard electrolysis catalysts. This study focused on understanding the adsorption mechanisms of byproducts related to the oxygen evolution reaction (OER) in anion exchange membrane (AEM) electrolysis, using Co₃O₄ as a typical non-precious metal catalyst. At the same time, efforts were made to develop a comprehensive free energy prediction model for more accurate predictions of OER results.

• 청정기술
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• 제14권3호
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• pp.176-183
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• 2008

본 연구의 목적은 노르말부텐을 이용하여 혼합옥텐을 합성하는 촉매와, 혼합옥텐을 합성가스와 함께 수소 포르밀 반응을 통해서 $C_9$-알데히드를 제조하기 위한 촉매를 개선하고자 하는 것이다. 노르말부텐의 이량화 반응을 위한 $Ni/A1_{2}O_3$ 촉매를 in-line 상태로 활성화 용액을 순환시키는 방법이 효과적이었다. 촉매의 비활성화의 원인을 분석한 결과, 이량화 반응실험에서 oligomer에 의한 촉매의 비활성화는 단순한 물리흡착 상태 또는 촉매의 세공 입구를 올리고머가 막는 현상 등에 의하여 반응활성점들이 반응에 참여하지 못하는 현상에 기인한 것으로 추정된다. 이량화 반응생성물 중에서 혼합옥텐을 분리하기 위하여 연속식 증류 장치를 사용하였는데, 환류비가 3 : 1 이상일 때 혼합옥텐의 순도가 99.57% 이상인 유분을 얻을 수 있었다. 혼합옥텐의 수소포르밀 반응에 의한 $C_9$-알데히드 제조 실험에서 Co 촉매계의 활성을 저하시키지 않으면서 촉매의 안정성을 높일 수 있는 배위자들의 성능을 조사한 결과, TPPO, NMP, NDMA, succinonitrile등이 초기 활성을 증가시키며, 촉매의 회수과정에서 Co의 손실을 줄일 수 있는 리간드로 적합한 것으로 나타났다.

• Korean Chemical Engineering Research
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• 제57권4호
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• pp.565-574
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• 2019

Fischer-Tropsch 합성공정은 합성가스로부터 탄화수소를 합성하는 대표적인 방법이며, 주로 철(Fe)계와 코발트(Co)계 촉매로 알려져 있다. 현재 생성물에 따라 일부 기술(CTL, GTL 등)은 상용 규모로 운전되고 있으나, 경질탄화수소와 중간유분을 직접 생산하는 연구는 아직 상용화되지는 않았다. 그러므로, 본 연구에서는 국내에서 현재까지 경질탄화수소와 중간유분을 직접 생산하기 위한 연구들을 정리하였으며, 촉매의 제조법, 조촉매 첨가, 제올라이트의 조합과 같은 영향이 생성물의 선택도에 미치는 영향을 고찰하였다.

• 한국표면공학회지
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• 제55권3호
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• pp.180-186
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• 2022

The production of hydrogen via water electrolysis (i.e., green hydrogen) using renewable energy is key to the development of a sustainable society. However, most current electrocatalysts are based on expensive precious metals and require the use of highly purified water in the electrolyte. We demonstrated the preparation of a non-precious metal catalyst based on CuCo₂O₄ (CCO) via simple electrodeposition. Further, an optimization process for electrodeposition potential, solution concentration and electrodeposition method was develop for a catalyst-substrate integrated electrode, which indicated the highly electrocatalytic performance of the material in electrochemical tests and when applied to an anion exchange membrane water electrolyzer.

• 한국표면공학회지
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• 제56권6호
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• pp.412-419
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• 2023

Anion exchange membrane electrolysis is considered a promising next-generation hydrogen production technology that can produce low-cost, clean hydrogen. However, anion exchange membrane electrolysis technology is in its early stages of development and requires intensive research on electrodes, which are a key component of the catalyst-system interface. In this study, we optimized the pressure conditions of the hot-pressing process to manufacture cobalt oxide electrodes for the development of a high uniformity and high adhesion electrode production process for the oxygen evolution reaction. As the pressure increased, the reduction of pores within the electrode and increased densification of catalytic particles led to the formation of a uniform electrode surface. The cobalt oxide electrode optimized for pressure conditions exhibited improved catalytic activity and durability. The optimized electrode was used as the anode in an AEMWE single cell, exhibiting a current density of 1.53 A cm^-2 at a cell voltage of 1.85 V. In a durability test conducted for 100 h at a constant current density of 500 mA cm^-2, it demonstrated excellent durability with a low degradation rate of 15.9 mV kh^-1, maintaining 99% of its initial performance.

• 대한화학회지
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• 제55권5호
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• pp.824-829
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• 2011

In Fischer-Tropsch Synthesis, because of few reactants ($H_2$, CO), scarce operating parameters affected on efficiency especially the selectivity of products. In this research, effect of operating parameters on the selectivity of Co-Mn-$TiO_2$ Fischer-Tropsch synthesis catalyst were studied by design of experimental procedure and Taguchi method. According to this research, interactions between operating factors have a crucial effect on light products selectivity. Among these interactions, (temperature${\times}$feed ratio) has the main influence on light hydrocarbons selectivity. It was concluded that temperature and feed ratio ($H_2$/CO) were the most integral operating parameters for much greater selectivity of light hydrocarbons.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.121-125
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• 2003

Enzymatic polymerization of cardol derived from cashew nut shell liquid have been examined. t-Butyl alcohol aqueous systems showed high yield of polycardol when SBP was as biocatalyst. Compared other solvents, peroxidase actiyity was maintained stable, which was seemed major cause. Solvent aqueous system and concentration of hydrogen peroxide were found to have an influence on the yield and molecular weight distribution of polycardol under the reaction of enzymatic polymerization using peroxidase. The polymer was subjected to the hardening by methyl ethyl ketone peroxide and cobalt naphthenate catalyst, giving a crosslinked tough film. Polycardol was cured rapidly and the hardness increased with time. Finally, the pencil scratch hardness reached to 7H, which is enough hard for industrial uses.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.296-298
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• 2005

Hydrogen generation by the hydrolysis of aqueous sodium borohydride $(NaBH_4)$ solutions was studied using IRA-400 anion resin dispersed Pt. Ru catalysts and Lithium Cobalt oxide $(LiCoO_2)$ supported Pt, Ru and PtRu catalysts. The performance of the $LiCoO_2$ supported catalysts is better than the ion exchange resin dispersed catalysts. There is a marked concentration dependence on the performance of the $LiCoO_2$ supported catalysts and the hydrogen generation rate goes down if the borohydride concentration is increased beyond $10\%$. The efficiency of PtRu- $LiCoO_2$ is almost double that of either Ru-$LiCoO_2$ or Pt-$LiCoO_2$ for $NaBH_4$ concentrations up to $10\%$.

• 반도체디스플레이기술학회지
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• 제7권4호
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• pp.45-49
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• 2008

For the commercialization of polymer electrolyte membrane fuel cell (PEMFC), some serious problems such as the decrease of platinum use as catalysts and a larger overpotential of oxygen reduction reaction (ORR) at cathode must be solved. In this study, 20%Pt/C and 20%PtCo/C catalysts for the cathode of PEMFC were synthesized from the chemical reduction method and evaluated using an electrochemical measurement. The ORR activity of synthesized 20%Pt/C and 20%PtCo/C had higher than that of the 20%Pt/C on the market. The synthesized 20%PtCo/C with the cobalt concentration (Pt:Co atomic ratio) from 5 to 20% showed the highest ORR activity.

• 약학회지
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• 제22권3호
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• pp.157-162
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• 1978

Total organic carbon(TOC) can be determined by means of combustion and flame ionization detector. The principle of string method is that a sample acidified to pH2 and transferred into combustion tube by string is oxidized with air. Another combustion tube method is that organic compounds are oxidized in the combustion tube charged with CuO and cobalt asbestos after the acidified sample is injected directly by microsyringe. Carbon dioxide evolved was reduced under specially treated nickel catalyst and hydrogen, the methane produced was detected by flame ionization detector. Linear relationship was found between concentration and the peak height by the string method. The peak area in the case of combustion tube method is in the range of 1-200ppm. The coefficient of variation by string method was 2.3% and that by combustion tube method was 1.8%. The lower detectable limit was about 10mol. Advantages of the latter are simplicity, sensitivity and reproducibility. TOC in contineous stream can also be determined automatically by means of the string method.