Carbon‐Encircled Pd‐Mn‐Cr Trimetal Oxide Electrocatalyst for Enhanced Oxygen Reduction Reaction in Alkaline Zn–Air Batteries

ABSTRACT In recent years, zinc‐air batteries (ZABs) have attracted growing interest due to their low cost, high safety, eco‐friendliness, and high theoretical energy density. However, the slow kinetics of the oxygen reduction reaction (ORR) frequently limit the performance of ZABs. In this study, a carbon‐encircling trimetal catalyst was synthesized to obtain Pd@CrMnO/C. Characterization results show that the Pd@CrMnO/C catalyst exhibited a sheet‐like morphology, with more well‐defined crystalline domains on the surface. Nitrogen adsorption–desorption measurements reveal that Pd@CrMnO/C exhibits the H4‐type hysteresis loop with surface area of 7.06 m 2 /g and an average pore size of 9.0 nm. The prepared Pd@CrMnO/C catalyst exhibits a half‐wave potential of 0.74 V for ORR, indicating an exceptional ORR catalytic activity, because of its extremely stable structure and large number of active sites. Compared to CrMnO/C and MnO/C, the ZAB with Pd@CrMnO/C exhibits a higher power density of 210.7 mW/cm 2 and an open‐circuit voltage of 1.46 V. Furthermore, after 400 cycles (>65 h), the Pd@CrMnO/C‐based ZAB exhibits a small drop in efficiency (0.5%), indicating greater long‐term stability. These findings suggest that Pd@CrMnO/C is a promising catalyst for energy storage technologies.