Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9759293 | International Journal of Hydrogen Energy | 2005 | 7 Pages |
Abstract
Lanthanum cobaltate and its strontium-substituted products have been prepared using a novel stearic acid sol-gel method at 600 °C. The oxide catalysts followed the rhombohedral hexagonal crystal geometry. Sr-substitution (0.2-0.4 mol) increased the oxide roughness as well as the apparent electrocatalytic activity greatly. The oxygen evolution on each oxide catalyst showed two Tafel slopes, one (b1â
65Â mV/decade) at low and the other (b2â
103Â mV/decade) at higher overpotentials. The reaction order w. r. t. OH- concentration was approximately unity. Values of thermodynamic parameters for the oxygen evolution reaction (OER), namely, the standard enthalpy of activation (ÎH#0) and standard entropy of activation (ÎS#0) were â¼126kJmol-1 and â¼112Jdeg-1mol-1 and â¼109kJmol-1 and â¼144Jdeg-1mol-1 on the base oxide and La0.6Sr0.4CoO3, respectively.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
B. Lal, M.K. Raghunandan, M. Gupta, R.N. Singh,