Effect of the CeO₂ synthesis route on alkaline OER electrocatalytic activity

This study compares the electrocatalytic performance of CeO₂ obtained through two synthesis routes: CeBDC MOF-derived CeO₂ and CeO₂ produced by direct calcination of cerium nitrate. Both materials were calcined at 700 °C, deposited onto nickel foam, and evaluated toward the oxygen evolution reaction in 1.0 mol L⁻¹ KOH. XRD, Raman, and SEM analyses confirmed the formation of the CeO₂ fluorite structure and revealed structural and morphological differences between the two routes. The MOF-derived CeO₂ exhibited lower microstrain, a shifted Raman F₂g mode, and superior electrocatalytic behavior, reaching 10 mA cm⁻² at a lower overpotential and with a smaller Tafel slope. These results indicate that MOF precursor engineering is a promising strategy to improve CeO₂ electrodes for water electrolysis.