Limits...
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

Koutechy-Levich (K-L) plots at different potentials for VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) electrodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4663630&req=5

f10: Koutechy-Levich (K-L) plots at different potentials for VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) electrodes.

Mentions: where J and JK are the measured and kinetic current density, is the rotation rate in the form of rpm, is the transferred electron number, is the Faraday constant (96485 C mol−1), is the concentration of O2 (1.210−6 mol cm−3), is the diffusion coefficient of O2 (1.910−5 cm2 s−1), is the kinematic viscosity (0.01 cm2 s−1) in 0.1 M KOH solution52. As shown in Fig 10, the electron transfer numbers of VOxNy, VOxNy-XC 72R and VOxNy-CNTs electrodes at all selected potentials increase in sequence with the average electron transfer numbers of 3.54, 3.82 and 3.90 respectively. Thus, this results indicate that VOxNy-CNTs catalyst exhibits a direct 4-electron dominated reduction process. And consistent with the analysis of EIS measurements, the increased number of electron transferred also suggests that the addition of carbon support can facilitate the transfer of electron from the surface of catalysts to oxygen molecule.


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)

Koutechy-Levich (K-L) plots at different potentials for VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) electrodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f10: Koutechy-Levich (K-L) plots at different potentials for VOxNy (A), VOxNy-XC 72R (B) and VOxNy-CNTs (C) electrodes.
Mentions: where J and JK are the measured and kinetic current density, is the rotation rate in the form of rpm, is the transferred electron number, is the Faraday constant (96485 C mol−1), is the concentration of O2 (1.210−6 mol cm−3), is the diffusion coefficient of O2 (1.910−5 cm2 s−1), is the kinematic viscosity (0.01 cm2 s−1) in 0.1 M KOH solution52. As shown in Fig 10, the electron transfer numbers of VOxNy, VOxNy-XC 72R and VOxNy-CNTs electrodes at all selected potentials increase in sequence with the average electron transfer numbers of 3.54, 3.82 and 3.90 respectively. Thus, this results indicate that VOxNy-CNTs catalyst exhibits a direct 4-electron dominated reduction process. And consistent with the analysis of EIS measurements, the increased number of electron transferred also suggests that the addition of carbon support can facilitate the transfer of electron from the surface of catalysts to oxygen molecule.

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