• 한국표면공학회지
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• 제56권4호
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• pp.243-249
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• 2023

Urea oxidation reaction (UOR) via electrochemical oxidation process can replace oxygen evolution reaction (OER) for green hydrogen production since UOR has lower thermodynamic potential (0.37 V_RHE) than that of OER (1.23 V_RHE). However, in the case of UOR, 6 electrons are required for the entire UOR. For this reason, the reaction rate is slower than OER, which requires 4 electrons. In addition, it is an important challenge to develop catalysts in which both oxidation reactions (UOR and OER) are active since the active sites of OER and UOR are opposite to each other. We prove that among the NiFe₂O₄ nanoparticles synthesized by the hydrothermal method at various synthesis temperatures, NiFe₂O₄ nanoparticle with properly controlled particle size and crystallinity can actively operate OER and UOR at the same time.

• 한국환경과학회지
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• 제8권6호
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• pp.725-730
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• 1999

The advanced oxidation process (AOP) using ozone combined with hydrogen peroxide and ultraviolet treatment were evaluated for biodegradable dissolved organic carbon (EDOC) formation and dissolved organic carbon (DOC) removal. Oxidation treatment were conducted alone or combination with ozone, hydrogen peroxide and ultraviolet processes. Ozone dosage of ozone process was varied from $0.5mg/l{\ell}\cdot}min$ to $5mg/{\ell}{\cdot}min$. Ozone/hydrogen peroxide process was done using $20mg/{\ell}{\cdot}min$ of hydrogen peroxide concentration. Ozone/ultraviolet process was irradiated with $12mW/cm^2$ of density and 254nm. Ozone dosage was varied from $0.5mg/{\ell}{\cdot}min$ to $5mg/{\ell}{\cdot}min$ at the ozone/hydrogen peroxide and ozone/ultraviolet processes too. Contact time of all the process was 20 minutes. Oxidation treatment were performed on microfiltration effluent samples. BDOC formation was reached to an optimum at ozone dosage of $1.5mg/{\ell}{\cdot}min$ in the ozone/hydrogen peroxide process and $1mg/{\ell}{\cdot}min$ in ozone/ultraviolet process, after which BDOC formation was decreased at higher ozone dosages. But BDOC formation was increased with ozone dosages increasing in ozone process. The efficiency of DOC removal was higher AOPs than ozone process. Ozone/ultraviolet proces was the highest for DOC removal efficiency in each process. THMFP. removal efficiency by ozone/ultraviolet process was higher than that by each of ozone process and ozone/hydrogen peroxide process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.152-152
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• 2013

Mechanism of energy conversion from chemical to electrical during exothermic catalytic reactions at the metal surfaces has been a fascinating and crucial subject in heterogeneous catalysis. A metal-semiconductor Schottky nanodiode is novel device for direct detection of chemically induced hot electrons which have sufficient energy to surmount the Schottky barrier. We measured a continuous chemicurrent during the hydrogen oxidation under of 760 Torr of O2 and 6 Torr of H2 by using Pt/Si and Pt/TiO2 nanodiodes at reaction temperatures and compared the chemicurrent with the reaction turnover rate. The thermoelectric current was measured by carrying out an experiment under O2 condition for elimination of the background current. Gas chromatograph and source meter were used for measurement of the chemical turnover rate and the chemicurrent, respectively. The correlation between the chemicurrent and the chemical turnover rate under hydrogen oxidation implies how hot electrons generated on the metal surface affect hydrogen oxidation.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.16-19
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• 2011

Oxidation products of ceftiofur were formed in hydrogen peroxide solution. The structures of the ceftiofur oxidation products were characterized by high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry (HPLC/ESI/MS/MS). The products were identified as compounds oxidized at the sulfur of a cephem ring. For further analysis, experiments were performed using $O^{18}$-labeled hydrogen peroxide. In addition, density-functional calculations were carried out for six possible oxidation products to support the experimental results.

• 공업화학
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• 제34권3호
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• pp.307-312
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• 2023

본 연구는 수소 경제 사회의 안전 확보를 위해 수소 연료전지 후단 배출된 미반응 수소를 안정적으로 산화하는 방안에 대해 논의하였다. 안전 시스템은 미반응 수소를 에너지원 없이 제거할 수 있는 상온 산화촉매를 충진하였으며, 이때 반응으로 배출되는 산화열은 안정적으로 회수할 수 있는 열 회수 장치를 연계하고자 하였다. 그 결과, 수소 산화 시스템의 충진 조건에 따라 시스템 내 압력 및 유체 흐름이 변화함을 CFD 분석을 통해 확인하였다. 또한 배가스 온도, 열 회수기 내 유량 및 압력조건을 최적화하여 300 ℃ 이상의 배가스 산화 열원을 40 ℃ 이상의 온수를 확보하는 방식으로 폐열을 회수할 수 있음을 확인하였다. 본 연구를 통해 수소 연료전지와 같은 중·소규모 사업장에 적용된 수소 활용 공정을 실증 규모로 평가하여 안전 시스템으로의 가능성을 확인하였다. 추후 실증화 연구를 통해 예측하지 못한 수소 안전사고에 대해 대응할 수 있는 안전 가이드로 활용될 수 있다고 판단된다.

• 약학회지
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• 제56권6호
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• pp.390-394
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• 2012

A series of new pyridazinyl sulfoxides 3a~e and pyridazinyl sulfones 4a were synthesized for development of candidates to retain anticancer activity. The utility of sulfoxides and sulfones in both laboratory and industrial practice was quickly recognized, and these species have been extensively utilized, including as pharmaceutical intermediates and anticancer agents. Alkylthiopyridazines 2a~e were prepared from the 3,6-dichloropyridazine using allylthiolation with alkyl mercaptan. Sulfides could be oxidized to sulfoxides or sulfones using 1~3 equivalents of hydrogen peroxide as an oxidant. The oxidation of sulfoxides to sulfones was also accomplished with aqueous hydrogen peroxide. Formation of 3a~e and 4a was undertaken with stirring using 35% hydrogen peroxide at room temperature in acetic acid for 18~72 h. Synthetic compounds were identified using NMR spectrum.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.524-527
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• 2000

An electroenzymatic system to oxidize veratryl alcohol of on electrodes with in-situ generated hydrogen peroxide was studied. We investigated hydrogen peroxide generation, current efficiency, and veratryl alcohol oxidation in the electrode system at various conditions. The reaction rates of veratryl alcohol oxidation were compared in an electrochemical, an electroenzymatic, and an usual biochemical systems to prove the concept of electroenzymatic oxidation.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.640-646
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• 2012

The effect of Ce promotion over 1wt% $Pt/{\gamma}-Al_2O_3$ catalysts on the CO conversion and $CO_2$ selectivity was investigated in preferential CO oxidation (PrOx) to reduce the CO concentration less than 10 ppm in excess $H_2$ stream for polymer electrolyte membrane fuel cell (PEMFC). Ce-promoted 1wt% $Pt/{\gamma}-Al_2O_3$ catalysts were prepared by incipient wetness impregnation method and the loading amount of Pt was fixed at 1wt%. The content of Ce promoter which has excellent oxygen storage and transfer capability due to the redox property was adjusted from 0 to 1.5wt%. Ce-promoted 1wt% $Pt/{\gamma}-Al_2O_3$ catalysts exhibit high CO conversion and $CO_2$ selectivity at low temperatures below $150^{\circ}C$ due to the improvement of reducibility of surface PtOx species compared with the 1wt% $Pt/{\gamma}-Al_2O_3$ catalyst without Ce addition. When Ce content was more than 1wt%, the catalytic activity was decreased at over $160^{\circ}C$ in PrOx because of competitive $H_2$ oxidation. As a result, 0.5wt% Ce is optimal content not only to achieve high catalytic activity and good stability at low temperatures below $150^{\circ}C$ in the presence of $CO_2$ and $H_2O$ but also to minimize the $H_2$ oxidation at high temperatures.

• 대한수의학회지
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• 제38권2호
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• pp.273-279
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• 1998

The ability of bovine intact red blood cells to scavenge superoxide and hydrogen peroxide by superoxide dismutase, catalase and glutathione peroxidase was investigated. Intact red cells(up to 0.4%) suspensions did not inhibit ferricytochrome c reduction by superoxide in the superoxide generating system. On the other hand, intact red cell(0.4%) suspensions almost completely inhibit ferrocytochrome c oxidation by hydrogen peroxide. The ability of intact red cells to scavenge hydrogen peroxide was mainly attributed to either membrane bound catalase or glutathione peroxidase. The scavenge of hydrogen peroxide by 0.1~0.2% intact red cells showed a trend of dependence on mainly glutathione peroxidase. However, at blood cell concentration higher than 0.3%, the process depended upon peroxidase-independent scavengers like catalase. Enhancement of ferrocytochrome c oxidation by red cells treated with aminotriazole proved that the protection against hydrogen peroxide was due to catalase, while the protection in the presence of glutathione indicated scavenging effect of glutathione peroxidase against hydrogen peroxide.

• 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.