Iron-Cobalt-Cerium Multimetallic Oxides Derived from Prussian Blue Precursors: Enhanced Oxygen Evolution Electrocatalysis

Exploring non-precious metal-based electrocatalysts is still challenging in 21(st) century. In this work, a series of hexagonal bipyramidal Ce-based PBA materials as precursors with different Fe/Co metal ratios, namely as CeFexCo1-x-PBA, are successfully constructed via co-precipitation method and converted into corresponding metal oxides (denoted as FexCo1-xCeOy) via thermal treatment. Then, they as electrocatalysts realize highly efficient oxygen evolution reaction (OER). Especially, as-synthesized Fe0.7Co0.3CeOy electrocatalyst shows very low overpotentials of 320 mV at the current density of 10 mA cm(-2) and the Tafel slop of 98.4 mV dec(-1) in 1 M KOH with remarkable durability for 24 h, which was due to the synergistic effect of multi-metal FeCoCe centers. Furthermore, a two-electrode cell of Fe0.7Co0.3CeOy/NF||Pt/C/NF realizes outstanding overall water splitting with a voltage of only 1.71 V at 10 mA cm(-2) and remarkable long-term durability, that is even superior to benchmark IrO2/NF||Pt/C/NF counterpart.