Elucidating Synergistic Effects of Different Metal Ratios in Bimetallic Fe/Co-N-C Catalysts for Oxygen Reduction Reaction

Catalysts

卷:11

Marius Gollasch¹  Henrike Schmies¹  Julia Müller-Hülstede¹  Dana Schonvogel¹  Peter Wagner¹  Alexander Dyck²  Michael Wark³ 

[1] German Aerospace Center, Institute for Engineering Thermodynamics, Carl-von-Ossietzky Straße 15, 26129 Oldenburg, Germany;

[2] German Aerospace Center, Institute for Networked Energy Systems, Carl-von-Ossietzky Straße 15, 26129 Oldenburg, Germany;

[3] Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany;

关键词: fuel cells;    ORR;    PGM-free;    Me-N-C;    AST;   

DOI  :  10.3390/catal11070841

来源: DOAJ

【 摘 要 】

Lowering or eliminating the noble-metal content in oxygen reduction fuel cell catalysts could propel the large-scale introduction of commercial fuel cell systems. Several noble-metal free catalysts are already under investigation with the metal-nitrogen-carbon (Me-N-C) system being one of the most promising. In this study, a systematic approach to investigate the influence of metal ratios in bimetallic Me-N-C fuel cells oxygen reduction reaction (ORR) catalysts has been taken. Different catalysts with varying ratios of Fe and Co have been synthesized and characterized both physically and electrochemically in terms of activity, selectivity and stability with the addition of an accelerated stress test (AST). The catalysts show different electrochemical properties depending on the metal ratio such as a high electrochemical mass activity with increasing Fe ratio. Properties do not change linearly with the metal ratio, with a Fe/Co ratio of 5:3 showing a higher mass activity with simultaneous higher stability. Selectivity indicators plateau for catalysts with a Co content of 50% metal ratio and less, showing the same values as a monometallic Co catalyst. These findings indicate a deeper relationship between the ratio of different metals and physical and electrochemical properties in bimetallic Me-N-C catalysts.

【 授权许可】

Unknown