Stabilizing Atomic Pt with Trapped Interstitial F in Alloyed PtCo Nanosheets for High-Performance Zinc-Air Batteries

Abstract

Recently, considerable attention has been given to the stabilization of atomic platinum (Pt) catalysts on desirable supports in order to reduce Pt consumption, improve the catalyst stability, and thereafter enhance the catalyst performance in renewable energy devices such as fuel cells and zinc-air battery (ZAB). Herein, we rationally designed a novel strategy to stabilize atomic Pt catalysts in the alloyed platinum cobalt (PtCo) nanosheets with trapped interstitial fluorine (SA-PtCoF) for ZAB. The trapped interstitial F atoms in PtCoF matrix induce lattice distortion resulting in weakening of Pt-Co bond, which is the driving force to form atomic Pt. As a result, the onset potentials of SA-PtCoF are 0.95 V and 1.50 V for oxygen reduction and evolution reactions (ORR and OER), respectively, superior to the commercial Pt/C@RuO2. When used in ZAB, the designed SA-PtCoF can afford a peak power density of 125 mW cm-2 with a specific capacity of 808 mAh gZn-1 and excellent cyclability over 240 h, surpassing the state-of-the-art catalysts.