کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6617410 459633 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of sol-derived Co-phenylene diamine/carbon materials as oxygen reduction catalysts in alkaline media
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Investigation of sol-derived Co-phenylene diamine/carbon materials as oxygen reduction catalysts in alkaline media
چکیده انگلیسی
Co-1,2-phenylenediamine (Co-pda) catalysts, dispersed on high surface area Vulcan Carbon (VC) or carbon nanotube (CNT) supports, and then heat-treated at between 500 and 1100 °C, demonstrate excellent performance as oxygen reduction (ORR) catalysts in alkaline media. While the ORR activity of carbon, and of pda on carbon, is shown to be quite good, adding Co to pda causes a notable further improvement (ca. 10 times) in the cathode activity. The Koutecky-Levich corrected Tafel data show that the best performance is obtained for the 900 °C heat-treated materials and a Co:pda molar ratio of 1:2 (22% Co nominally), similar to the case in acidic solutions. The transfer coefficient (α) is close to 1 for the best catalysts, suggesting that a chemical step following a first electron transfer step is rate determining. Further, the low H2O2 yield indicates that the predominant reaction pathway involves the direct 4-electron reduction of O2 to water. All of these ORR performance characteristics are essentially independent of the type of carbon powder substrate used, consistent with the proposal that the ORR active sites arise from the surface product formed by the thermal decomposition of pda.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 105, 30 August 2013, Pages 170-179
نویسندگان
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