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Changes in Active Sites on Nitrogen‐Doped Carbon Catalysts Under Oxygen Reduction Reaction: A Combined Post‐Reaction Characterization and DFT Study
Author(s) -
Jain Deeksha,
Zhang Qiang,
Hightower Jonathan,
Gustin Vance,
Asthagiri Aravind,
Ozkan Umit S.
Publication year - 2019
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201901883
Subject(s) - catalysis , chemistry , electrochemistry , x ray photoelectron spectroscopy , rotating disk electrode , carbon fibers , inorganic chemistry , electrolyte , density functional theory , nitrogen , protonation , oxygen , oxygen reduction reaction , cyclic voltammetry , materials science , electrode , chemical engineering , organic chemistry , computational chemistry , ion , composite material , composite number , engineering
Nitrogen‐doped carbon nanostructures (CN x ) have been shown to be promising catalysts to replace Pt‐based materials for oxygen reduction reaction (ORR) in PEM fuel cell cathodes. This work reports the use of a combination of post‐reaction X‐ray photoelectron spectroscopy (XPS) and density functional theory (DFT) aimed at examining changes to the nitrogen species in CN x after potential application in an oxygen saturated acidic electrolyte. The results hence obtained reveal interesting changes to the pyridinic, quaternary and pyridinic N + O − binding energy envelopes as a result of protonation of sites and formation of ORR intermediates after the CN x electrodes were subjected to electrochemical potential holds in the kinetic and mass transfer limited regimes of the ORR cyclic voltammogram of the catalyst.