کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
193161 459763 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Average turn-over frequency of O2 electro-reduction for Fe/N/C and Co/N/C catalysts in PEFCs
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Average turn-over frequency of O2 electro-reduction for Fe/N/C and Co/N/C catalysts in PEFCs
چکیده انگلیسی

This work aims to evaluate the average turn-over frequency of O2 electro-reduction for the catalytic sites resulting from the heat-treatment of iron- or cobalt-acetate and carbon black in ammonia at high temperature. This task is complex because at least three factors may control the activity of such catalysts: their metal content, nitrogen content and micropore specific area. In this work, the activity was measured for metal contents from 0.005 to 5 wt.%. The time of heat-treatment was tuned to keep the micropore specific area constant. At Fe content ≤0.2 wt.% the activity increases linearly with Fe content, thus enabling the average turn-over frequency of the Fe/N/C site to be determined. At Co content ≤1.0 wt.% the activity increases approximately as the square root of the Co content. Because no linear relation was found, the turn-over frequency of the Co/N/C site could not be determined. For both Fe and Co catalysts, the activity drops dramatically at contents >1 wt.%. This is concurrent with a drop in the micropore specific area of the catalysts.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 52, Issue 19, 25 May 2007, Pages 5975–5984
نویسندگان
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