• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.44-48
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• 2014

Sulfonated poly(arylene ether sulfone)-cerium composite membranes with improved oxidative stability were prepared for proton exchange membrane fuel cell application. Oxidative stability of the composite membranes changed depending on the amount of incorporated metal. Their water uptake, IEC and proton conductivity were also affected. ICP analysis confirmed trace of cerium ion in the composite membranes and $^1H$-NMR indicated successful coordination of sulfonic acid groups with the metal ions. Increasing amount of the cerium ion resulted in decrease in proton conductivities and water uptake, but enhanced oxidative stabilities. A hydrogen peroxide exposure equipment was used for the test of oxidative stability of the composite membranes, which enabled to mimic fuel cell operating condition compared with conventional Fenton's test.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.31-35
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• 2016

This paper demonstrates the successful application of yttria-stabilized zirconia thin films deposited by atomic layer deposition to the anode-side interlayer for cerium oxide electrolyte based solid oxide fuel cell. At the operating temperature over $500^{\circ}C$, the electrical conductivity of cerium oxide electrolyte is known to dramatically increase and, therefore, the open circuit voltage of the cell decreases leading to the decrease of the performance. Ultra-thin (60 nm) atomic layer deposited yttria-stabilized zirconia thin film in this study conformally coated the anode-side surface of the cerium oxide electrolyte and efficiently blocked the electrical conduction through the electrolyte. Accordingly, the open circuit voltage increased by up to 20%, and the maximum power density increased by 52% at $500^{\circ}C$

• Proceedings of the KSEEG Conference
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• 2000.04b
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• pp.293-294
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• 2000

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.99-100
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• 2009

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.377-378
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• 2011

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.513-518
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• 2005

Catalytic oxidation of toluene on the manganese oxide catalysts and manganese-cerium oxide catalysts was investigated. The catalysts were characterised by X-ray diffraction(XRD), thermo gravimetric analyzer(TGA), toluene-temperature program reduction(Toluene-TPR). We found that the optimal manganese content was 18.2 wt.% and the optimal cerium content was 10.0 wt.% at catalytic oxidation of toluene. It is shown that ceria improves the activity of manganese oxide phases. From the XRD results, it was estimated that $MnO_2$ phase was active site in the monometallic and bimetallic catalysts. From the TGA and Toluene-TPR results, it show that ceria improves the mobility of the lattice oxygen, adequate oxidation state of the active phase, reduction ability at low temperature, and re-oxidation of the active site.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.1
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• pp.1-5
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• 2019

The physical properties of ceramic materials including oxides are greatly influenced by the material density. Therefore, various efforts have been made to increase the material density. One of the most popular strategies is to use sintering additives in sintering materials. The conventional sintering additive was a spherical powder having a three-dimensional structure. In this study, sintering additive with 2-dimensional (2D) layer structure was used to increase the sintering density of cerium oxide and its effect was confirmed. In this study, 1 nm-thick $TiO_x$ and $MnO_x$ nanosheets were used as sintering additives.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.277-277
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• 2007

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.113-119
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• 2012

The two-step water splitting thermochemical cycle is composed of the T-R (Thermal Reduction) and W-D (Water Decomposition) steps. The mechanism of this cycle is oxidation-reduction, which produces hydrogen. The reaction temperature necessary for this thermochemical cycle can be achieved by a dish-type solar thermal collector (Inha University, Korea). The purpose of this study is to validate a water splitting device in the field. The device is studied and fabricated by Kodama et al (2010, 2011). The validation results show that the foam device, when loaded with $CeO_2$ powder, was successfully achieved hydrogen production under field conditions. Through this experiment, we can analyze the characteristics of the catalyst and able to determine which is more advantageous thing to produce hydrogen compared with previous experiment that used ferrite-device.

• Journal of the Korean Chemical Society
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• v.38 no.10
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• pp.705-709
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• 1994

The kinetics of the oxidation reaction of malonic acid by ceric ion in 1 M sulfuric acid solution at $20^{\circ}C$ have been investigated by spectrophotometric method. The reaction rate at a large excess of malonic acid was found to be pseudo-first order. The observed pseudo-first order rate constants, $k_{obs}$, are dependent on the concentration of malonic acid, [MA], of which relationship has been found to be $k_{obs}$ = (0.592[MA])/(1+14.5[MA]$^2$). A mechanism for the reaction has been suggested on the basis of the above rate equation. The rate determining step may be the electron transfer reaction between enolate type malonate anion, which is formed by the acid dissociation reaction of malonic acid, and Ce(IV). The rate depression in the range of high concentration of MA has been explained by the formation of 1 : 2 chelate between Ce(IV) and malonate. According to the mechanism, the pH dependence of the rate, which was studied by Sengupta et al., has also been explained.