High Pt utilization efficiency of electrocatalysts for oxygen reduction reaction in alkaline media

Electrocatalyst for oxygen-reduction reaction (ORR) is crucial for metal-air batteries, in which Pt-based materials are the benchmark catalysts for ORR. However, the high cost and limited supplies of Pt limit its broad use in commercial applications. Designing highly efficient Pt electrocatalysts can reduce material cost and enable commercial success for a wide variety of electrochemical technologies. Herein, we prepared Pt/MnO x and Pt/MnO electrocatalysts via deposition–precipitation and H 2 –reduction approaches. The Pt mass activities towards the ORR at 0.7 V for the Pt/MnO x , and Pt/MnO catalysts were 4.0 and 3.7 A mg Pt −1 , respectively, which were 20, and 18.5 times as commercial 20% Pt/C catalyst. The transferred electron numbers (n) were 3.6 and 4.0 for Pt/MnO x and Pt/MnO, respectively. Moreover, Pt/MnO catalyst exhibited a good ORR stability after 500 cycles compared to Pt/MnO x catalyst in 0.1 M KOH.