期刊
SOLID STATE IONICS
卷 216, 期 -, 页码 78-82出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.ssi.2011.12.013
关键词
Co-phthalocyanine; Catalysis; Oxygen reduction reaction (ORR); XPS; NEXAFS
For polymer-electrolyte-membrane fuel cells (PEM-FC), platinum catalysts on carbon based substrates are state of the art, due to high electrochemical activity and chemical stability in acid electrolytes. High costs of platinum force investigations of alternative catalysts. With respect to the oxygen reduction reaction, possible candidates are transition metal (TM) complexes like TM-porphyrines or TM-phthalocyanines. Pyrolysis on carbon based substrates improves the catalytic activity. Highest activities were found for Fe or Co as transition metal centers. We present results of the pyrolysis of Co-phthalocyanine (CoPc) on carbon black. Besides an investigation of morphology by scanning electron microscopy (SEM) and chemical composition by energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) during pyrolysis, we present a near edge Xray absorption fine structure (NEXAFS) study of the chemical composition for the related annealing steps. This investigation is accompanied by an electrochemical characterization of the catalytic activity and selectivity. The XPS and NEXAFS data indicate a decomposition of the CoN4 (chelate-) complex during pyrolysis. The N1s data for 800 degrees C show graphite-like, formally pyrrolic and pyridinic like features, without any significant contribution of Co. The Co2p data for both, XPS and NEXAFS are dominated by CoO/Co2O3. It can be concluded that during the pyrolysis cobalt particles are formed by the disintegration of CoN4-centers, after pyrolysis these particles become oxidized upon contact with air. (C) 2012 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据