Towards understanding the active sites for the ORR in N-doped carbon materials through fine-tuning of nitrogen functionalities: an experimental and computational approach
authors Quilez-Bermejo, J; Melle-Franco, M; San-Fabian, E; Morallon, E; Cazorla-Amoros, D
nationality International
journal JOURNAL OF MATERIALS CHEMISTRY A
keywords OXYGEN-REDUCTION REACTION; SURFACE-CHEMISTRY; CATALYTIC-ACTIVITY; ALLOY CATALYSTS; METAL; ELECTROCATALYSTS; GASES; POLYANILINE; ADSORPTION; ELECTRODES
abstract The design of advanced N-doped carbon materials towards oxygen reduction reaction (ORR) catalysis is only possible if the nature of the active sites is fully understood. There is an important piece of research seeking to overcome this challenge through experimental or theoretical results. However, the combination of both approaches is necessary to deepen the knowledge about this subject. This work presents excellent agreement between experimental results and computational models, which provides evidence of the nature of the most active sites in N-doped carbon materials. N-doped carbon materials have been experimentally obtained through double stage treatment of polyaniline in distinct atmospheres (both oxygen-containing and inert atmospheres) at different temperatures (800-1200 degrees C). According to temperature programmed desorption (TPD), Raman spectroscopy, N-2-adsorption isotherms at -196 degrees C and X-ray photoelectron spectroscopy (XPS), this synthesis method results in the selective formation of nitrogen species, without significant changes in structural order or porosity. ORR catalytic tests evidence the highly efficient catalysis, with platinum-like performance in terms of the current density and onset potential, of N-doped carbon materials selectively containing graphitic-type nitrogen species. Computational chemistry, through DFT calculations, shows that edge-type graphitic nitrogen is more effective towards ORR catalysis than pyridinic, pyrrolic, pyridonic, oxidized and basal-type graphitic nitrogen species.
publisher ROYAL SOC CHEMISTRY
issn 2050-7488
isbn 2050-7496
year published 2019
volume 7
issue 42
beginning page 24239
ending page 24250
digital object identifier (doi) 10.1039/c9ta07932g
web of science category Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary
subject category Chemistry; Energy & Fuels; Materials Science
unique article identifier WOS:000494830400012
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journal analysis (jcr 2019):
journal impact factor 11.301
5 year journal impact factor 10.694
category normalized journal impact factor percentile 91.814
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