Realizing extraordinary bifunctional electrocatalytic performance of layered perovskite through Ba-site Gd doping toward oxygen reduction and evolution reactions

Abstract

Herein we propose a Ba-site Gd doping protocol in layered perovskites, demonstrating highly active bifunctional PrBa1-xGdxCo2O5+δ electrocatalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Benefiting from enhanced oxygen surface exchange and chemical diffusion kinetics, resultant PrBa0.95Gd0.05Co2O5+δ (PBG0.05CO) exhibits an area-specific resistance (ASR) of 0.038 Ω cm2 at 700 oC, reduced by ∼46.5% relative to undoped PrBaCo2O5+δ (PBCO). When evaluated as the air electrode, the as-fabricated single coin fuel cell delivers a peak power density (PPD) of 1230 mW cm-2 at 700 oC. For the CO2-electrolysis at 750 oC, the large current density (J) of 2630 mA cm-2 is achieved in the PBG0.05CO anode-based electrolysis cell at a voltage (V) of 1.8 V. Furthermore, exceptional operating stability is realized in both ORR and OER manners. Our findings highlight an effective strategy to optimize the electrocatalytic properties of layered perovskites, endowing potential applications in energy storage and conversion aspects.