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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

Nyquist plots corresponding to all referred electrodes in 0.1 M KOH solution from 100 kHz-1 Hz; The inset shows the low impedance region.
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f8: Nyquist plots corresponding to all referred electrodes in 0.1 M KOH solution from 100 kHz-1 Hz; The inset shows the low impedance region.

Mentions: On the other hand, the increased overall conductivity also contributes to the decrease of overpotential as demonstrated before50. To further monitor the different conductivity of Pt/C and all VOxNy-based electrodes, representative Nyquist plots of electrochemical impedance spectroscopy (EIS) are displayed in Fig. 8, where the high frequency region (see the inset) can be associated with the charge-transfer process as well as the properties of electrochemical reaction resistance and the low frequency straight lines relate to the properties of the diffusion process51. It is obvious that the initial resistances corresponding to the combination of solution resistance and the film resistance are 39.3, 40.2, 40.6 and 41.4 Ω for VOxNy-CNTs, VOxNy-XC 72R, commercial Pt/C and bare VOxNy electrodes respectively, which indicates the enhanced electrochemical conductivity due to the introduction of carbon support for VOxNy catalyst. Moreover, the apparent arc-shaped region for just bare VOxNy electrode which is relative to the charge-transfer resistance is also responsible for its large ORR overpotential. Thus, the highest overall conductivity of VOxNy-CNTs is beneficial to the higher ORR onset potential, i.e., the lower overpotential.


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)

Nyquist plots corresponding to all referred electrodes in 0.1 M KOH solution from 100 kHz-1 Hz; The inset shows the low impedance region.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f8: Nyquist plots corresponding to all referred electrodes in 0.1 M KOH solution from 100 kHz-1 Hz; The inset shows the low impedance region.
Mentions: On the other hand, the increased overall conductivity also contributes to the decrease of overpotential as demonstrated before50. To further monitor the different conductivity of Pt/C and all VOxNy-based electrodes, representative Nyquist plots of electrochemical impedance spectroscopy (EIS) are displayed in Fig. 8, where the high frequency region (see the inset) can be associated with the charge-transfer process as well as the properties of electrochemical reaction resistance and the low frequency straight lines relate to the properties of the diffusion process51. It is obvious that the initial resistances corresponding to the combination of solution resistance and the film resistance are 39.3, 40.2, 40.6 and 41.4 Ω for VOxNy-CNTs, VOxNy-XC 72R, commercial Pt/C and bare VOxNy electrodes respectively, which indicates the enhanced electrochemical conductivity due to the introduction of carbon support for VOxNy catalyst. Moreover, the apparent arc-shaped region for just bare VOxNy electrode which is relative to the charge-transfer resistance is also responsible for its large ORR overpotential. Thus, the highest overall conductivity of VOxNy-CNTs is beneficial to the higher ORR onset potential, i.e., the lower overpotential.

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