Abstract
The reversible oxygen-binding properties of the polyethyleneimine-cobalt (PEI-Co) complex and the effect of the PEI-Co complex on the reduction current of oxygen were studied. The color of the PEI-Co complex in the electrolyte solution changed on exposure to oxygen atmosphere, which was monitored by UV-visible absorption spectrometry. The UV-visible absorption spectra of the PEI-Co complex displayed a new adsorption band at 310 nm, with an isosbestic point at 280 nm. The spectral change was attributed to the reversible oxygen-adduct formation of the PEI-Co complex even in the electrolyte solution. The oxygen-binding equilibrium curve of the PEI-Co complex obeyed a Langmuir isotherm, to give the high oxygen-binding affinity (p50 = 0.667 kPa). And the apparent dissociation rate constant of oxygen from the PEI-Co complex (kd = 1.1 × 105 s-1) was also high. The aqueous solution of the PEI-Co complex that had rapid and reversible oxygen-binding properties functioned as an oxygen-enriching medium for oxygen electrode to enhance the diffusion-controlled current for the oxygen reduction. Based on the rapid release of oxygen from the PEI-Co complex, a high current was obtained for the reduction of oxygen in the presence of the PEI-Co complex, and the current increased with the increase of the concentration of the PEI-Co complex and the oxygen concentration in the atmosphere. The reduction current reached a saturated value near [ethyleneimine unit]/[Co] = 5, which suggested the structure of a six-coordinate μ-dioxo dinuclear complex [N 5CoIII-O2-CoIIIN5]. A new type of oxygen-diffusion electrode for metal/air batteries and fuel cells is proposed using the oxygen-enriching material immobilized at the electrode surface.
| Original language | English |
|---|---|
| Pages (from-to) | 859-863 |
| Number of pages | 5 |
| Journal | Acta Polymerica Sinica |
| Issue number | 6 |
| Publication status | Published - 2004 Dec |
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Keywords
- Oxygen electrode
- Polyethyleneimine-cobalt complex
- Reduction current
- Reversible oxygen-binding
ASJC Scopus subject areas
- Polymers and Plastics
- Materials Chemistry
Cite this
Effect of the polyethyleneimine-cobalt complex on reduction current of oxygen. / Shentu, Baoqing; Weng, Zhixue; Nishide, Hiroyuki.
In: Acta Polymerica Sinica, No. 6, 12.2004, p. 859-863.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of the polyethyleneimine-cobalt complex on reduction current of oxygen
AU - Shentu, Baoqing
AU - Weng, Zhixue
AU - Nishide, Hiroyuki
PY - 2004/12
Y1 - 2004/12
N2 - The reversible oxygen-binding properties of the polyethyleneimine-cobalt (PEI-Co) complex and the effect of the PEI-Co complex on the reduction current of oxygen were studied. The color of the PEI-Co complex in the electrolyte solution changed on exposure to oxygen atmosphere, which was monitored by UV-visible absorption spectrometry. The UV-visible absorption spectra of the PEI-Co complex displayed a new adsorption band at 310 nm, with an isosbestic point at 280 nm. The spectral change was attributed to the reversible oxygen-adduct formation of the PEI-Co complex even in the electrolyte solution. The oxygen-binding equilibrium curve of the PEI-Co complex obeyed a Langmuir isotherm, to give the high oxygen-binding affinity (p50 = 0.667 kPa). And the apparent dissociation rate constant of oxygen from the PEI-Co complex (kd = 1.1 × 105 s-1) was also high. The aqueous solution of the PEI-Co complex that had rapid and reversible oxygen-binding properties functioned as an oxygen-enriching medium for oxygen electrode to enhance the diffusion-controlled current for the oxygen reduction. Based on the rapid release of oxygen from the PEI-Co complex, a high current was obtained for the reduction of oxygen in the presence of the PEI-Co complex, and the current increased with the increase of the concentration of the PEI-Co complex and the oxygen concentration in the atmosphere. The reduction current reached a saturated value near [ethyleneimine unit]/[Co] = 5, which suggested the structure of a six-coordinate μ-dioxo dinuclear complex [N 5CoIII-O2-CoIIIN5]. A new type of oxygen-diffusion electrode for metal/air batteries and fuel cells is proposed using the oxygen-enriching material immobilized at the electrode surface.
AB - The reversible oxygen-binding properties of the polyethyleneimine-cobalt (PEI-Co) complex and the effect of the PEI-Co complex on the reduction current of oxygen were studied. The color of the PEI-Co complex in the electrolyte solution changed on exposure to oxygen atmosphere, which was monitored by UV-visible absorption spectrometry. The UV-visible absorption spectra of the PEI-Co complex displayed a new adsorption band at 310 nm, with an isosbestic point at 280 nm. The spectral change was attributed to the reversible oxygen-adduct formation of the PEI-Co complex even in the electrolyte solution. The oxygen-binding equilibrium curve of the PEI-Co complex obeyed a Langmuir isotherm, to give the high oxygen-binding affinity (p50 = 0.667 kPa). And the apparent dissociation rate constant of oxygen from the PEI-Co complex (kd = 1.1 × 105 s-1) was also high. The aqueous solution of the PEI-Co complex that had rapid and reversible oxygen-binding properties functioned as an oxygen-enriching medium for oxygen electrode to enhance the diffusion-controlled current for the oxygen reduction. Based on the rapid release of oxygen from the PEI-Co complex, a high current was obtained for the reduction of oxygen in the presence of the PEI-Co complex, and the current increased with the increase of the concentration of the PEI-Co complex and the oxygen concentration in the atmosphere. The reduction current reached a saturated value near [ethyleneimine unit]/[Co] = 5, which suggested the structure of a six-coordinate μ-dioxo dinuclear complex [N 5CoIII-O2-CoIIIN5]. A new type of oxygen-diffusion electrode for metal/air batteries and fuel cells is proposed using the oxygen-enriching material immobilized at the electrode surface.
KW - Oxygen electrode
KW - Polyethyleneimine-cobalt complex
KW - Reduction current
KW - Reversible oxygen-binding
UR - http://www.scopus.com/inward/record.url?scp=14944369597&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=14944369597&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:14944369597
SP - 859
EP - 863
JO - Acta Polymerica Sinica
JF - Acta Polymerica Sinica
SN - 1000-3304
IS - 6
ER -