Cobalt and Iron Complexes with N-heterocyclic Ligands as Pyrolysis Precursors for Oxygen Reduction Catalysts

Roncaroli, Federico; Molin, Emiliano S. Dal; Viva, Federico A.; Bruno, Mariano M.; Halac, Emilia B.

doi:10.1016/j.electacta.2015.05.136

Cited by 50 publications

(47 citation statements)

References 51 publications

(108 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This enables the adsorption of molecular oxygen and its intermediates in the ORR due to the increased electron-donor property of carbon. 41 From the N1s spectra, the N1s peak is observed to be deconvoluted into two forms of nitrogen binding configurations, which are pyridinic-N (~398 eV) and pyrrolic-N (~400 eV) in both the catalysts. 41 From the N1s spectra, the N1s peak is observed to be deconvoluted into two forms of nitrogen binding configurations, which are pyridinic-N (~398 eV) and pyrrolic-N (~400 eV) in both the catalysts.…”

Section: Physical Characterizationmentioning

confidence: 99%

“…15 Graphitic-N denotes a nitrogen atom in a graphite plane, which is attached to three carbon atoms, whereas pyrrolic-N refers to nitrogen atoms within a fivemembered ring with two p electrons. 41 From the N1s spectra, the N1s peak is observed to be deconvoluted into two forms of nitrogen binding configurations, which are pyridinic-N (~398 eV) and pyrrolic-N (~400 eV) in both the catalysts. The percentage of the pyridinic-N in Fe-NCNT and Co-NCNT is 55.15% and 45.88%, respectively, whereas the pyrrolic-N content is 44.85% for Fe-NCNT and 54.12% for Co-NCNT.…”

Section: Physical Characterizationmentioning

confidence: 99%

See 1 more Smart Citation

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

et al. 2019

View full text Add to dashboard Cite

Summary The application of nonprecious metal catalysts, such as iron (Fe) and cobalt (Co) catalyst, to direct liquid fuel cells (DLFCs), especially in direct methanol fuel cells, has been widely investigated. However, the application of such non‐Pt catalysts as cathode catalysts in direct formic acid fuel cell (DFAFC) operations has not yet been investigated. This study intends to evaluate the formic acid tolerance of such catalysts in case of oxygen reduction reaction. In addition, we investigate their performances in DFAFC using the Fe‐ and Co‐nitrogen‐doped carbon nanotubes (Fe‐NCNT and Co‐NCNT) as the cathode catalysts and compare these performances with the commercial Pt/C catalyst. Herein, Fe‐NCNT and Co‐NCNT were synthesized using the conventional method by the pyrolysis of the multiwalled carbon nanotubes, dicyandiamide, and metal salt under the flow of N2 at 800°C. Both the Fe‐NCNT and Co‐NCNT catalysts exhibit higher formic acid tolerance when compared with that exhibited by the Pt/C catalyst. Further, single‐cell tests with hydrogen‐fed polymer electrolyte fuel cell (PEFC) and DFAFC operations were conducted under various operating conditions to compare the performances of the cells while using the prepared catalysts and the conventional Pt/C catalyst. The PEFC performances in both the Fe‐NCNT and Co‐NCNT catalysts were significantly low (94.9mW cm−2 for Fe‐NCNT and 164.0 mW cm−2 for Co‐NCNT at 60°C). Regardless, the Co‐NCNT catalyst exhibited a maximum power density of 160.7 mW cm−2 in DFAFC operated at 60°C and7‐M formic acid. This value is comparable with that for DFAFC with a Pt/C catalyst (128.9mW cm−2) and is considerably higher than that obtained for other DLFCs while using a non‐Pt catalyst. Therefore, the usage of a non‐Pt metal catalyst as the cathode catalyst is preferable in case of DFAFC.

show abstract

Section: Physical Characterizationmentioning

confidence: 99%

Section: Physical Characterizationmentioning

confidence: 99%

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

et al. 2019

View full text Add to dashboard Cite

show abstract

“…[148,149] At present, Pt catalysts are commonly employed for the reductiono fO 2 to H 2 O. However,h igh costs, toxicity,a nd low earth abundance of Pt has led scientists to investigate the de-velopment of Pt-freeO RR catalysts. [150,151] One major drawback in the reduction of O 2 to give H 2 Oi st he high redox potential of 0.815 Vvs. NHE at pH 7.…”

Section: Oxygen Reduction Reaction (Orr)mentioning

confidence: 99%

“…Five-membered ring systems have been shown to possess higher efficiency towards H 2 O 2 formationa sc omparedt ot heir six-membered counterparts that showed H 2 Of ormation. [151] Doping of carbon-rich supports with transition metals, for example, Fe, Co, Cu, Mn, or Ni, represents an additional modification to alter the activity of ORR activem aterials. [198][199][200][201][202][203][204] In this regard, transition-metal phthalocyanines (Pc) supported by graphitized carbonb lack (GCB) showed high activity towards ORR in O 2 -saturated 0.1 m KOH solutions.…”

Section: Heterogeneous Catalysts For Orrmentioning

confidence: 99%

From Enzymes to Functional Materials—Towards Activation of Small Molecules

Möller

Piontek

Miller

et al. 2017

Chemistry A European J

View full text Add to dashboard Cite

The design of non-noble metal-containing heterogeneous catalysts for the activation of small molecules is of utmost importance for our society. While nature possesses very sophisticated machineries to perform such conversions, rationally designed catalytic materials are rare. Herein, we aim to raise the awareness of the overall common design and working principles of catalysts incorporating aspects of biology, chemistry, and material sciences.

show abstract

“…revealed that different coordination environments in precursors can influence the ORR activities of metal‐organic framework‐derived Fe−N−C electrocatalysts . Other studies have also reported the synthesis of M−N−C through the use of metal‐coordinated N precursors . However, to rationally design and synthesize highly active Fe−N−C electrocatalysts, it is required to understand how the precursor coordination state affects Fe−N x active site formation during high‐temperature pyrolysis.…”

Section: Introductionmentioning

confidence: 99%

Rational Generation of Fe−N_x Active Sites in Fe−N−C Electrocatalysts Facilitated by Fe−N Coordinated Precursors for the Oxygen Reduction Reaction

et al. 2019

View full text Add to dashboard Cite

FeÀ NÀ C catalysts synthesized by pyrolysis of Fe and N precursors have been intensively studied due to their remarkable activities for the electrochemical oxygen reduction reaction (ORR). Although FeÀ N 4 coordinated structures have been suggested as active sites by recent spectroscopic studies, the influence of precursor coordination on the generation of the active sites during high-temperature pyrolysis is not well understood. In this work, phenanthroline isomers were used as systematic model precursors to reveal the correlation between precursor coordination and active site formation in FeÀ NÀ C catalysts. Coordination between Fe and each phenanthroline isomer was effectively controlled by the molecular structure: monodentate (1,7-and 4,7-phenanthroline) and bidentate coordination (1,10-phenanthroline). Through X-ray absorption spectroscopy and X-ray photoelectron spectroscopy study, large difference in atomic distribution of both Fe and N was revealed; the preferential formation of Fe-N x active sites was featured only in Fe(1,10-phenanthroline)/KB with homogeneously distributed Fe and highly retained pyridinic N. With Fe-N x active site moieties, Fe(1,10-phenanthroline)/KB exhibited superior ORR activity and stability in alkaline half-cell and full-cell tests. These results highlight the importance of the use of precursors with multiple coordination (i. e. bidentate) for the effective derivation of Fe-N x active sites for highly active and stable ORR electrocatalysts.

show abstract

Cobalt and Iron Complexes with N-heterocyclic Ligands as Pyrolysis Precursors for Oxygen Reduction Catalysts

Cited by 50 publications

References 51 publications

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

From Enzymes to Functional Materials—Towards Activation of Small Molecules

Rational Generation of Fe−N_x Active Sites in Fe−N−C Electrocatalysts Facilitated by Fe−N Coordinated Precursors for the Oxygen Reduction Reaction

Contact Info

Product

Resources

About

Cobalt and Iron Complexes with N-heterocyclic Ligands as Pyrolysis Precursors for Oxygen Reduction Catalysts

Cited by 50 publications

References 51 publications

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

Performance of direct formic acid fuel cell using transition metal‐nitrogen‐doped carbon nanotubes as cathode catalysts

From Enzymes to Functional Materials—Towards Activation of Small Molecules

Rational Generation of Fe−Nx Active Sites in Fe−N−C Electrocatalysts Facilitated by Fe−N Coordinated Precursors for the Oxygen Reduction Reaction

Contact Info

Product

Resources

About

Rational Generation of Fe−N_x Active Sites in Fe−N−C Electrocatalysts Facilitated by Fe−N Coordinated Precursors for the Oxygen Reduction Reaction