On the effect of sulfite ions on the structural composition and ORR activity of Fe-N-C catalysts

被引：5

作者：

Wagner, S. ^{[1
,3
]}

Martinaiou, I. ^{[1
,3
]}

Shahraei, A. ^{[2
,3
]}

Weidler, N. ^{[1
]}

Kramm, U. I. ^{[1
,2
,3
]}

机构：

[1] Tech Univ Darmstadt, Dept Mat & Earth Sci, Alarich Weiss Str 2, D-64287 Darmstadt, Germany

[2] Tech Univ Darmstadt, Grad Sch Excellence Energy Sci & Engn, Otto Berndt Str 3, D-64287 Darmstadt, Germany

[3] Tech Univ Darmstadt, Dept Mat & Earth Sci, Otto Berndt Str 3, D-64287 Darmstadt, Germany

来源：

HYPERFINE INTERACTIONS | 2018年 / 239卷

关键词：

Fe-N-C catalyst; Mossbauer spectroscopy; PEMFC; oxygen reduction reaction; OXYGEN-REDUCTION REACTION; FUEL-CELLS; FE/N/C CATALYSTS; SITES; IRON; ELECTROCATALYSTS; MOSSBAUER; DENSITY; CARBON; SPECTROSCOPY;

D O I：

10.1007/s10751-017-1485-8

中图分类号：

O64 [物理化学（理论化学）、化学物理学]; O56 [分子物理学、原子物理学];

学科分类号：

070203 ; 070304 ; 081704 ; 1406 ;

摘要：

Fe-N-C catalysts are the most promising group of non-precious metal catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC). This study focusses on two different porphyrin-based Fe-N-C catalysts and a Fe-N-C catalyst prepared from alternative precursors under S-addition. Catalysts are subjected to a wet-chemical poisoning treatment by sulfite ions . A mechanism for the deactivation process of the active sites is proposed. ORR activity is evaluated for the original catalysts (OC) and for the poisoned catalysts in 0.1 M H2SO4. In addition, the structural composition of the catalysts is identified by Mobauer spectroscopy. Our results show that the sulfite ions bound irreversible to the catalysts and the catalysts lose significant fractions of their ORR activity while in Mobauer spectroscopy a new doublet appears. Based on the results, possible models for the binding of the ambident sulfite ion to the FeN4 centers are discussed.

引用

页数：12

共 30 条

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