• 제목/요약/키워드: Chemical stability

검색결과 3,497건 처리시간 0.03초

폴리올 에스테르의 합성 및 열 안정성 (Synthesis and Thermal Stability of Polyol Esters)

  • 정근우;백진욱;김영운;서인옥;한정식
    • Tribology and Lubricants
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    • 제18권5호
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    • pp.319-323
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    • 2002

  • Polyol esters were synthesized by condensation reaction of polyols (PE and DiPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

  • https://doi.org/10.9725/kstle.2002.18.5.319 인용 PDF KSCI

Effect of Cobalt Loading on the Performance and Stability of Oxygen Reduction and Evolution Reactions in Rechargeable Zinc-air Batteries

  • Sheraz Ahmed;Joongpyo Shim;Gyungse Park
    • 대한화학회지
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    • 제68권2호
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    • pp.87-92
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    • 2024

  • The commercialization of rechargeable metal-air batteries is extremely desirable but designing stable oxygen reduction reaction (ORR) catalysts with non-noble metal still has faced challenges to replace platinum-based catalysts. The nonnoble metal catalysts for ORR were prepared to improve the catalytic performance and stability by the thermal decomposition of ZIF-8 with optimum cobalt loading. The porous carbon was obtained by the calcination of ZIF-8 and different loading amounts of Co nanoparticles were anchored onto porous carbon forming a Co/PC catalyst. Co/PC composite shows a significant increase in the ORR value of current and stability (500 h) due to the good electronic conductive PCN support and optimum cobalt metal loading. The significantly improved catalytic performance is ascribed to the chemical structure, synergistic effects, porous carbon networks, and rich active sites. This method develops a new pathway for a highly active and advantageous catalyst for electrochemical devices.

  • https://doi.org/10.5012/jkcs.2024.68.2.87 인용 PDF HTML