Effects of Ni, Fe, Cu, and Cr substitutions for Co in La{sub 0.8}Sr{sub 0.2}CoO{sub 3} on electrocatalytic properties for oxygen evolution
- Banaras Hindu Univ., Varanasi (India)
The influence of some transition metal ion substitutions in the active 0.2 mole strontium-doped lanthanum cobaltate (La{sub 0.8}Sr{sub 0.2}Co{sub 1-y}B{sub y}O{sub 3} with B = Ni, Fe, Cu, and Cr; 0.1 {<=} y {<=} 0.4) lattice was studied on the electrocatalytic properties of the oxide by cyclic voltammetry and Tafel polarization techniques. The cyclic voltammetry showed a pair of redox peaks prior to the onset of oxygen evolution, regardless of the nature of the substitution. The presence of Fe or Ni, in small quantities enhanced the electrochemically active area. The anodic polarization studies indicated two Tafel slopes: {approximately}2.3 RT/F at low and {approximately}2(2.3 RT/F) at high overpotentials. The oxygen evolution reaction on each B-site substituted perovskite followed first-order kinetics with respect to OH{sup {minus}} ion concentration. The La{sub 0.8}Sr{sub 0.2}Co{sub 0.9}Fe{sub 0.1}O{sub 3} and La{sub 0.8}Sr{sub 0.2}Co{sub 0.9}Ni{sub 0.1}O{sub 3} electrodes showed the highest electrocatalytic activity based on geometrical surface area. Copper and chromium substitutions had detrimental effects on the electrocatalytic activity.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 256801
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 5 Vol. 143; ISSN 0013-4651; ISSN JESOAN
- Country of Publication:
- United States
- Language:
- English
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