• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.172-177
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• 1985

The semiconducting property of Sb-doped tin oxide thin film electrode was investigated and the electrocatalytic effect of this electrode for $SO_2$ (or sulfite, bisulfite ions) oxidation reaction was studied under various conditions. The anodic oxidation of $SO_2$ at tin oxide thin film electrode commenced at lower potential with increasing pH, and good electrocatalytic effect was shown of $SO_3^=$ oxidation in basic solution. In the acidic solutions the electrocatalytic effect of platinum-or palladium-incorporated tin oxide electrode was found to be due to the sites of Pt or Pd exposed on the electrode surface. The electrocatalytic effect of tin oxide electrode was distinctive from that of Pt-or Pd-containing electrodes.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.191.2-191.2
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• 2016

$TiO_2$는 우수한 화학적 및 물리적 안정성 때문에 수전해 장기간 사용에 적합한 전기화학 전극으로 여겨진다. 큰 표면적을 갖는 $TiO_2$를 제조하기 위한 수많은 방법 중 양극산화(anodization)는 비교적 간단하고 저렴한 공정으로 인하여 매우 실용적인 방법으로서 알려져 있다. 특히, 고도로 정렬 된 $TiO_2$ 나노튜브($TiO_2$ NTs) 의 경우에는 분말상과 달리 전극제조를 위해 추가적인 접착제를 필요하지 않다. 그러나, $TiO_2$는 일반적으로 절연 특성을 나타내기 때문에 전극의 활용을 위해서는 본질적으로 촉매의 사용이 불가피하다. 다수의 전기 촉매 중, $IrO_2$와 $RuO_2$는 수전해 분야에 잘 알려진 산화 촉매이다. 그럼에도 불구하고, 특유의 높은 종횡비 때문에 $TiO_2$ 나노튜브에 전기 촉매를 균일하게 도핑하는 것은 많은 어려움이 따른다. 이를 해결하기 위한 방법으로 $RuO_2$를 도핑하기 위한 단일공정 $TiO_2$ 양극산화 기술이 보고된 바 있다. 본 연구에서는 2원 촉매($IrO_2$ 및 $RuO_2$)를 $TiO_2$ 나노튜브에 도핑하기 위한 단일공정 양극산화 기술에 대하여 연구하였다. 전구물질로써 $KRuO_4$($RuO_2$ 전구체)와 IrOx 나노입자(IrOx NPs, $IrO_2$ 전구체)를 사용하였다. 특히, IrOx를 나노 입자는 $IrCl_3$로부터 중간 매체로 합성된다. IrOx는 단일공정 양극산화 중에 $TiO_2$ 나노튜브 상에 도핑 가능한 이온 형태인 $IrO_4$-로 전환될 수 있다. 제조된 시료는 열처리 후 바로 전극으로 사용되었으며 SEM, XPS, TEM, ICP-OES 등으로 정성, 정량 분석을 수행하였다. LSV와 EIS를 통해 전기화학적 성능 평가가 이루어졌으며, LSV를 통해 포집한 기체는 가스 크로마토그래피를 사용하여 정량분석한 후 그 효율을 측정하였다.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.744-752
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• 1993

Electrochemical reduction of thionyl chloride has been carried out at glassy carbon and microelectrode that modified by macrocyclic compounds. The catalyst molecules of macrocyclic compounds were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. The concentration of catalysts and electrode immersion time were found to affect the catalyst performance strongly. Significant improvements in cell performance have been noted in terms of both exchange rate constants of up to 10 times and power densities of up to 220% at glassy carbon electrode. The diffusion coefficients obtained at carbon microelectrode were slightly different from that determined at glassy carbon electrode.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.154-161
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• 2022

The carbon-neutrality induced by the global warming is important for the modern society. Hydrogen has been received the attention as a new energy source to replace the fossil fuels. Polymer electrolyte membrane fuel cells, which convert the chemical reaction energy of hydrogen into electric power directly, are a type of eco-friendly power for future vehicles. Due to the sluggish oxygen reduction reaction and costly Pt catalyst in the cathode, the research related to the replacement of Pt-based catalysts has been vitally carried out. In this case, however, the performance is significantly different from each other and a variety of factors have existed. In this review paper, we rearrange and summarize relevant papers published within 5 years approximately. The selection of precursors, synthesis method, and co-catalyst are represented as a core factor, while the necessity of research for the further enhancement of activity may be raised. It can be anticipated to contribute to the replacement of precious metal catalysts in the various fields of study. The final objective of the future research is depicted in detail.

• 한국전기화학회:학술대회논문집
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• 1998.10a
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• pp.19-19
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• 1998

• Clean Technology
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• v.30 no.1
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• pp.55-61
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• 2024

Efforts are actively underway to address the issues related to the high cost of Pt-based catalysts for oxygen reduction reactions by designing high-performance Pt-based alloys through the control of their nanostructures. In this study, a method was proposed to control the nanostructure of Pt-based alloys, either hollow or core-shell, by adjusting the pH of the solution during the galvanic replacement reaction between the carbon-supported nickel-nickel nitride composite and the Pt ions. The physical characteristics, including the state, quantity, and morphology of the metal particles under different preparation conditions, were evaluated through X-ray diffraction, transmission electron microscopy, and inductively coupled plasma. When the prepared catalysts were employed for the oxygen reduction reaction, they exhibited an improvement in area specific-activity compared to a commercial Pt/C, with a 1.7 and 1.9-fold enhancement for the hollow and core-shell structured catalysts, respectively.

• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.132-137
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• 2010

This study is concerned the electrocatalytic generation of oxygen gas at electrochemically deposited manganese oxide electrode in KOH solution. Manganese oxide nanoparticles electrodeposited onto relatively substrate, e.g glassy carbon, Au, Ti electrode. MnOx is electrodeposited in nanorod structure which cover the overall surface of the substrate. The $\gamma$-MnOOH that is kind of manganese oxide species plays a significant role as a catalytic mediator, which promote 4-electron reduction process. Modified electrodes with electrodeposited manganese oxide structures resulted in significant decrease in the anodic polarization compared with the unmodified electrodes in alkaline media.

• Journal of the Korean Electrochemical Society
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• v.12 no.2
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• pp.131-141
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• 2009

The conversion of carbon dioxide to value-added compounds has been attracted to solve the environmental problems due to the climate change caused by greenhouse effect in addition to recycle the abundant and renewable carbon source. For utilizing carbon dioxide to useful compounds, the development of catalysts and optimization of experimental conditions are indispensable since carbon dioxide is the most stable one among carbon compounds and the a certain amount of energy is required for the carbon dioxide conversion. The technologies developed for the electrochemical carbon dioxide conversion were reviewed in terms of electrocatalyst which can be electrode material, inorganic complex, and enzyme. This field should be developed further since no good catalyst having selectivity, efficiency, and stability all together.

• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.79-84
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• 2024

Methane is an abundant and renewable hydrocarbon, but it causes global warming as a greenhouse gas. Therefore, methods to convert methane into useful chemicals or energy sources are needed. Methanol is a simple and abundant chemical that can be synthesized by the partial oxidation of methane. Methanol can be used as a chemical feedstock or a transportation fuel, as well as a fuel for low-temperature fuel cells. However, the electrochemical oxidation of methanol is a complex and multi-step reaction. To understand and optimize this reaction, new electrocatalysts and reaction mechanisms are required. This review discusses the methanol oxidation reaction mechanism, recent research trends, and future research directions.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.05a
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• pp.121-125
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• 1994

전극물질 및 전극촉매로서의 세라믹물질의 중요성은 상당히 크다. magneli phase를 갖는 $Ti_4O_{7}$과 rock salt구조를 갖는 TiO등의 티타늄 아산화물들은 전도성 세라믹으로서 전기전도도는 탄소보다도 좋으며, 높은 산화전위에서도 산화되지 않을 뿐만아니라, 강산용액에서도 내식성이 강하여 $SO_2$나 $O_2$의 산화전극 물질로 사용할 수 있다. $SO_2$나 $O_2$의 산화에 뛰어난 활동도를 보이는 촉매인 Pt나 Ru를 전기화학적으로 $Ti_4O_{7}$이나 TiO에 입혀서 그 전기화학적인 특성을 조사하였다.