Besides precious metal oxides, non-noble metal oxides are found to be promising materials especially, in the alkaline medium for OER. In this work, Co/MO2 (M = Ti, Zr, and Ce) catalysts were synthesized without using any harsh steps such as pyrolization, annealing, calcination, and carbonization. Cobalt nanoparticles with similar to 2.6 nm particle size were loaded on metal oxides by simple impregnation and reduction method. Considering the low onset and overpotential values, low Tafel slopes, high exchange current densities, high TOF values, as well as high Faradaic efficiency, Co/CeO2, Co/ZrO2, and Co/TiO2 nanocatalysts show the remarkable electrocatalytic performance in 1 M KOH for OER. Moreover, no noticeable change in the performance of Co/MO2 (M = Ti, Zr, and Ce) catalysts were observed after the stability test at 10 mA.cm(-2). This work will also shed light on other studies, in the preparation of inexpensive, earth abundant, and highly active OER electrocatalysts via changing impregnated metals or metal oxides supports. (C) 2021 Elsevier Ltd. All rights reserved.