Electrochemical oxygen reduction (ORR) is a challenging approach for the sustainable production of hydrogen peroxide (H2O2) and is also a reaction of relevance in fuel-cell applications. Here, we propose an outstanding metal-free electrocatalyst for the unexpectedly selective ORR to H2O2, consisting of graphitized N-doped single-wall carbon nanohorns (CNHs). The catalyst can operate at acidic pH to a faradic efficiency as high as 98%, but it also shows excellent performance at either physiological or alkaline pH. Moreover, the very positive onset potentials observed at all pH values investigated (+0.40 V, +0.53 V, and +0.71 V at pH 1.0, 7.4, and 13.0, respectively), good stability, and excellent reproducibility make this material a benchmark catalyst for ORR to H2O2. The outstanding activity arises from a combination of several factors, such as CNH-dependent facilitation of electron delivery, suitable porosity, and a favorable distribution of the types of N atoms.

N-Doped Graphitized Carbon Nanohorns as a Forefront Electrocatalyst in Highly Selective O 2 Reduction to H 2 O 2

Iglesias, Daniel;Giuliani, Angela;Melchionna, Michele
;
Marchesan, Silvia;CRIADO FERNANDEZ, ALEJANDRO;Tavagnacco, Claudio;Prato, Maurizio
;
Fornasiero, Paolo
2018

Abstract

Electrochemical oxygen reduction (ORR) is a challenging approach for the sustainable production of hydrogen peroxide (H2O2) and is also a reaction of relevance in fuel-cell applications. Here, we propose an outstanding metal-free electrocatalyst for the unexpectedly selective ORR to H2O2, consisting of graphitized N-doped single-wall carbon nanohorns (CNHs). The catalyst can operate at acidic pH to a faradic efficiency as high as 98%, but it also shows excellent performance at either physiological or alkaline pH. Moreover, the very positive onset potentials observed at all pH values investigated (+0.40 V, +0.53 V, and +0.71 V at pH 1.0, 7.4, and 13.0, respectively), good stability, and excellent reproducibility make this material a benchmark catalyst for ORR to H2O2. The outstanding activity arises from a combination of several factors, such as CNH-dependent facilitation of electron delivery, suitable porosity, and a favorable distribution of the types of N atoms.
14-dic-2017
Pubblicato
http://www.cell.com/chem/fulltext/S2451-9294(17)30441-2
File in questo prodotto:
File Dimensione Formato  
10.1016_j.chempr.2017.10.013.pdf

non disponibili

Tipologia: Documento in Versione Editoriale
Licenza: Digital Rights Management non definito
Dimensione 3.76 MB
Formato Adobe PDF
3.76 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2915748
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 214
  • ???jsp.display-item.citation.isi??? 213
social impact