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Porous VO(x)N(y) nanoribbons supported on CNTs as efficient and stable non-noble electrocatalysts for the oxygen reduction reaction.

Huang K, Bi K, Lu YK, Zhang R, Liu J, Wang WJ, Tang HL, Wang YG, Lei M - Sci Rep (2015)

Bottom Line: Novel nanocomposites of carbon nanotubes supported porous VO(x)N(y) nonoribbons (VO(x)N(y)-CNTs) have been synthesized by the annealing of the sol-gel mixture of CNTs and V2O5 under NH3 atmosphere as well as the ageing process in air.Besides the morphological and structural characterizations revealed by TEM, SEAD, EDS, XRD and XPS measurements, typical electrochemical tests including cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry have been employed to determine the oxygen reduction reaction (ORR) performance of VO(x)N(y)-CNTs.Therefore, we have reasonable grounds to believe that this new VO(x)N(y)-CNTs nanocomposites can be regarded as a promising non-precious methanol-tolerant ORR catalyst candidate for alkaline fuel cells.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Information Photonics and Optical Communications &School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China.

ABSTRACT
Novel nanocomposites of carbon nanotubes supported porous VO(x)N(y) nonoribbons (VO(x)N(y)-CNTs) have been synthesized by the annealing of the sol-gel mixture of CNTs and V2O5 under NH3 atmosphere as well as the ageing process in air. Besides the morphological and structural characterizations revealed by TEM, SEAD, EDS, XRD and XPS measurements, typical electrochemical tests including cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry have been employed to determine the oxygen reduction reaction (ORR) performance of VO(x)N(y)-CNTs. Inspiringly, the results indicate that VO(x)N(y)-CNTs catalyst exhibits a 0.4 mA/cm(2) larger diffusion-limited current density, a 0.10  V smaller onset potential value, a 10.73% less of ORR current decay and an excellent methanol-tolerance compared with commercial Pt/C catalyst. Therefore, we have reasonable grounds to believe that this new VO(x)N(y)-CNTs nanocomposites can be regarded as a promising non-precious methanol-tolerant ORR catalyst candidate for alkaline fuel cells.

No MeSH data available.


Related in: MedlinePlus

ORR polarization curves of VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) as electrocatalysts in O2-saturated 0.1 M KOH solution.
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f9: ORR polarization curves of VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) as electrocatalysts in O2-saturated 0.1 M KOH solution.

Mentions: Furthermore, since the ORR is a multi-electron charge transfer reaction with two main possible paths in alkaline electrolyte: one is one step direct pathway, involving four electrons transfer to produce while the other one is two steps indirect pathway, involving two electrons transfer to produce and then the get another two electrons to transform into , rotating disk electrode (RDE) voltammetry (i.e. linear-sweep voltammetry, LSV) was performed in oxygen-saturated 0.1 M KOH solution at a scan rate of 5 mV/s with the rotation rate from 400 to 2000 rpm to gain further insight into the ORR process. Figure 9 shows that all VOxNy-based electrodes display elevated ORR current densities with the increase of rotation rate and VOxNy-CNTs perform best in view of all above three electrochemical parameters. In addition, the numbers of electrons transferred per oxygen molecule in ORR have been estimated on the basis of the well-known Koutechy-Levich (K-L) equation:


Porous VO(x)N(y) nanoribbons supported on CNTs as efficient and stable non-noble electrocatalysts for the oxygen reduction reaction.

Huang K, Bi K, Lu YK, Zhang R, Liu J, Wang WJ, Tang HL, Wang YG, Lei M - Sci Rep (2015)

ORR polarization curves of VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) as electrocatalysts in O2-saturated 0.1 M KOH solution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663630&req=5

f9: ORR polarization curves of VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) as electrocatalysts in O2-saturated 0.1 M KOH solution.
Mentions: Furthermore, since the ORR is a multi-electron charge transfer reaction with two main possible paths in alkaline electrolyte: one is one step direct pathway, involving four electrons transfer to produce while the other one is two steps indirect pathway, involving two electrons transfer to produce and then the get another two electrons to transform into , rotating disk electrode (RDE) voltammetry (i.e. linear-sweep voltammetry, LSV) was performed in oxygen-saturated 0.1 M KOH solution at a scan rate of 5 mV/s with the rotation rate from 400 to 2000 rpm to gain further insight into the ORR process. Figure 9 shows that all VOxNy-based electrodes display elevated ORR current densities with the increase of rotation rate and VOxNy-CNTs perform best in view of all above three electrochemical parameters. In addition, the numbers of electrons transferred per oxygen molecule in ORR have been estimated on the basis of the well-known Koutechy-Levich (K-L) equation:

Bottom Line: Novel nanocomposites of carbon nanotubes supported porous VO(x)N(y) nonoribbons (VO(x)N(y)-CNTs) have been synthesized by the annealing of the sol-gel mixture of CNTs and V2O5 under NH3 atmosphere as well as the ageing process in air.Besides the morphological and structural characterizations revealed by TEM, SEAD, EDS, XRD and XPS measurements, typical electrochemical tests including cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry have been employed to determine the oxygen reduction reaction (ORR) performance of VO(x)N(y)-CNTs.Therefore, we have reasonable grounds to believe that this new VO(x)N(y)-CNTs nanocomposites can be regarded as a promising non-precious methanol-tolerant ORR catalyst candidate for alkaline fuel cells.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Information Photonics and Optical Communications &School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China.

ABSTRACT
Novel nanocomposites of carbon nanotubes supported porous VO(x)N(y) nonoribbons (VO(x)N(y)-CNTs) have been synthesized by the annealing of the sol-gel mixture of CNTs and V2O5 under NH3 atmosphere as well as the ageing process in air. Besides the morphological and structural characterizations revealed by TEM, SEAD, EDS, XRD and XPS measurements, typical electrochemical tests including cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry have been employed to determine the oxygen reduction reaction (ORR) performance of VO(x)N(y)-CNTs. Inspiringly, the results indicate that VO(x)N(y)-CNTs catalyst exhibits a 0.4 mA/cm(2) larger diffusion-limited current density, a 0.10  V smaller onset potential value, a 10.73% less of ORR current decay and an excellent methanol-tolerance compared with commercial Pt/C catalyst. Therefore, we have reasonable grounds to believe that this new VO(x)N(y)-CNTs nanocomposites can be regarded as a promising non-precious methanol-tolerant ORR catalyst candidate for alkaline fuel cells.

No MeSH data available.


Related in: MedlinePlus