PHYSICOCHEMICAL AND ELECTROCATALYTIC PROPERTIES OF LANIO3 PREPARED BYA LOW-TEMPERATURE ROUTE FOR ANODE APPLICATION IN ALKALINE WATER ELECTROLYSIS

LaNi1-xFexO3 (x = 0, 0.25, 0.5) has been synthesized by the hydroxide solid solution precursor method for electrochemical characterization a s oxygen anode in strongly alkaline medium. Studies were made at the o xide him, which was obtained by the oxide-slurry painting technique. T he cyclic voltammetric study showed the formation of a diffusion-contr olled quasireversible redox couple, Ni(II)/Ni(III), (E(0) similar to 4 30 +/- 10 mV) at the oxide surface in 1 M KOH. The reaction was observ ed to follow approximately first-order kinetics in OH- concentration. Values of the Tafel slope ranged between 59 and 86 mV decade(-1) with all the oxide film electrodes. The electrocatalytic activity was found to be greatest with the Ni/LaNi0.75Fe0.25O3 electrode. A comparison w as made between the electrocatalytic activities of LaNiO3 prepared by the hydroxide solid solution precursor and by the hydroxide coprecipit ation technique.