Publisher： John Wiley & Sons Inc
E-ISSN： 1521-3757|127|43|12944-12948
ISSN： 0044-8249
Source： ANGEWANDTE CHEMIE, Vol.127, Iss.43, 2015-10, pp. : 12944-12948
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
AbstractFundamental understanding of non‐precious metal catalysts for the oxygen reduction reaction (ORR) is the nub for the successful replacement of noble Pt in fuel cells and, therefore, of central importance for a technological breakthrough. Herein, the degradation mechanisms of a model high‐performance Fe‐N‐C catalyst have been studied with online inductively coupled plasma mass spectrometry (ICP‐MS) and differential electrochemical mass spectroscopy (DEMS) coupled to a modified scanning flow cell (SFC) system. We demonstrate that Fe leaching from iron particles occurs at low potential (<0.7 V) without a direct adverse effect on the ORR activity, while carbon oxidation occurs at high potential (>0.9 V) with a destruction of active sites such as FeNxCy species. Operando techniques combined with identical location‐scanning transmission electron spectroscopy (IL‐STEM) identify that the latter mechanism leads to a major ORR activity decay, depending on the upper potential limit and electrolyte temperature. Stable operando potential windows and operational strategies are suggested for avoiding degradation of Fe‐N‐C catalysts in acidic medium.
Related content
Access to resources
Recommend
