Effect of partial substitution of Cr on electrocatalytic properties of MnFe2O4 towards O2-evolution in alkaline medium

Some Cr-substituted manganese ferrites have been synthesized by a precipitation method in order to reduce the oxygen overpotential on the MnFe2O4 surface. The study showed that Cr substitution from 0.1 to 1.0mol considerably improved the electrocatalytic activity of the oxide for the oxygen evolution reaction (OER). Values of the Tafel slope and the order for the OER with respect to OH- concentration were similar to 2 x 2.303RT/3F and similar to 2 and similar to 2.303RT/F and similar to 1.5 at low and high over potentials, respectively. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.