Noble Metal‐Free High Entropy Perovskite Oxide with High Cationic Dispersion Enhanced Oxygen Redox Reactivity

Abstract

AbstractHigh entropy perovskite oxide (HEPO) materials have received significant interest as efficient electrocatalysts owing to their chemical and structural stability, effective interaction of multiple metal active sites with the reaction intermediate species resulting in enhanced catalytic activity. The effect of high‐entropy strategy could achieve the regulation of the structural durability by tailoring the composition. Herein, we design a novel transition metal and rare‐earth metal based high entropy perovskite oxide (Co0.11Mn0.11Ni0.11Fe0.14La0.13Nd0.13Gd0.13Pr0.13)O3, showing superior catalytic activity in the oxygen reduction reaction (ORR) and also promising electrocatalyst in oxygen evolution reaction (OER). High degree of cationic dispersion in the lattice and multiple electrocatalytic active sites enhance the oxygen ion migration at the surface and facilitate electron transfer, manifesting good ORR performance. Notably, the as‐prepared high entropy material exhibits onset and half‐wave potential of 1.02 V and 0.89 V versus RHE, respectively, exceeding the performance of the benchmarked Pt/C catalyst in the ORR process with reasonable redox kinetics. Moreover, the material also presents faster kinetics with reasonably low overpotential and excellent electrochemical stability in the OER process as well. This study shows the viability of designing non‐precious high entropy materials as highly efficient oxide electrocatalyst by utilizing its broad compositional space.