• 세라미스트
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• 제21권4호
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• pp.366-377
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• 2018

Solid oxide fuel cells (SOFCs) are promising eco-friendly energy conversion system due to their high efficiency, low pollutant emission and fuel flexibility. High operating temperatures, however, leads to the crucial drawbacks such as incompatibility between the components and high thermal stress. Proton-conducting ceramic fuel cells (PCFCs) with proton-conducting oxide (PCO) materials are new types of fuel cells that can solve the problems of conventional SOFCs. Many studies have been proceeded to improve the performance of electrolytes and electrodes, and triple conductive oxides (TCOs) have attracted significant attention as high performance PCFC electrodes.

• Korean Chemical Engineering Research
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• 제57권5호
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• pp.596-605
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• 2019

프로톤 전도성 세라믹인 페로브스카이트 구조의 산화물은 고온 환경에서 고체 전해질 및 촉매로써 동시에 활용이 가능하여, 반응과 분리기능을 동시에 갖춘 멤브레인 반응기로 적용하기에 우수한 소재이다. 특히 수소 제조 촉매와 분리, 이를 결합한 멤브레인 반응기 개발에 관한 연구는 전해질 내 도핑 금속의 종류 및 온도, 반응물의 조성 등에 따라 다양한 연구 결과가 제시되고 있다. 이에 본 총설에서는 프로톤 전도성 세라믹반응기에서 메탄을 활용하여 수소 제조촉매와 멤브레인 반응기로 응용해 온 연구 동향을 살펴보고, 차세대 수소의 제조와 분리 기술로서의 응용분야 및 전망에 관해 고찰하고자 한다.

• The Korean Journal of Ceramics
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• 제4권2호
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• pp.136-140
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• 1998

This work demonstrates a method for modeling of electrical conductivity in high-temperature proton-conducting oxides. Total conductivity was calculated assuming that it comprises partial conductivities contributed by protons, oxygen ions and electron holes. From the polt $\sigma_{tot}$ vs. $po_2\;{1/4}$ in wet atmosphere, thermodynamic and kinetic parameters were obtained representing transport properties such as concentration and mobility of the charge-carrying defects. The formulas for the calculation of partial conduction were derived based on the defect structure of HTPCs. Illustrative calculation were made for $SrCe_{0.95}Yb_{0.05}O_{2.975}$ system.

• 공업화학
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• 제24권4호
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• pp.337-343
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• 2013

멤브레인 반응기는 멤브레인과 반응기를 결합하여 반응과 분리의 단위공정을 하나로 결합함으로써 전체공정을 단순화하고 반응효율을 높이고자 하는 혁신 기술로써, 멤브레인을 이용한 생성물의 선택적 제거를 통해 열역학적 평형을 뛰어넘는 전환율, 부반응물 생성 억제에 의한 반응 효율 및 선택성을 향상시킬 수 있다. 특히 이온전도성 세라믹을 이용한 멤브레인 반응기는 연료전지의 개발, 고순도 산소/수소의 분리/정제, 이산화탄소의 전환 및 다양한 화학제품제조에 까지 응용될 수 있기 때문에 시장의 확대와 더불어 크게 발전할 수 있을 것으로 기대된다. 본 총설에서는 수소이온 전도성 세라믹 멤브레인 반응기에 대한 연구동향과 다양한 응용분야 및 향후 전망 등에 고찰해 보고자 한다.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.213-221
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• 1998

$BaCe_{0.9}Gd_{0.1_O_{2.95}$ powder was synthesized by oxalate coprecipitation method. Precipitate with a stoichimetric ratio of the cations was prepared by adding a mixture of Ba, Ce and Gd nitrate solution to an oxalic acid solution at pH 4. Reaction between the constituent oxides to form a perovskite phase was initiated at $800^{\circ}C$ and a single phase $BaCe_{0.9}Gd_{0.1_O_{2.95}$ powder having good sinterability was obtained after calcination at $1000^{\circ}C$. Sintering green compacts of this powder for 6 h showed a considerable densification to start at $1100^{\circ}C$ and resulted in 93% and 97% relative densities at $1300^{\circ}$ and at $1450^{\circ}C$, respectively. Whereas the power compacts prepared by solid state reaction had lower relative densities, 78% at $1300^{\circ}$and 90% at $1450^{\circ}C$. Fine particles of $CeO_2$ second phase were observed in the surface of the sintered compacts. This was attributed to the evaporation of BaO from the surface that had been exposed during thermal etching.

• 한국수소및신에너지학회논문집
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• 제22권1호
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• pp.92-99
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• 2011

Barium cerate ($BaCeO_3$) related perovskite ceramics currently dominate the high-temperature proton conductor field. Unfortunately, these materials have very stringent environmental limitations necessitating the costly and complex conditioning or cleaning of the application feed-gas. Commercial realization has been hampered, in part, because of the reactivity of $BaCeO_3$ with $CO_2$, and to some extent $H_2O$. And sintered $BaCeO_3$ decomposed at a rate comparable to the powder samples. In this article, the chemical stability and the structural changes of $BaCe_{0.9-X}Y0.1La_XO_{3-\delta}$ (X=0, 0.1, 0.2) have been systematically investigated in the atmosphere containing carbon dioxide ($CO_2$) and water vapor ($H_2O$). The sintering characteristics were studied in $1600^{\circ}C$, sintered pellets disintegrate and decompose upon contacting boiling water on the surface only.