Trifunctional GdCoO3 perovskite electrocatalysts for zinc–air battery and water electrolysis applications

Abstract

Oxygen electrocatalysts are fascinating due to the absolute necessity of replacing expensive precious metal catalysts in electrochemical energy storage and conversion systems. The GdCoO₃ perovskite on N-doped carbon is synthesised using mechanochemical ball-milling followed by pyrolysis. The GdCoO₃ on the N-doped carbon composite exhibits better ORR and OER activity with a minimum ΔE value of 0.74 V compared to many other Gd-based perovskites reported in the literature. This material shows promising mass activities estimated from kinetic current densities for the ORR and OER as 18.4 and 19.4 A g⁻¹, respectively. Besides, the materials show HER activity with an overpotential of 0.241 V and a mass activity of 27.7 A g⁻¹. The zinc–air battery performance was demonstrated with a power density comparable to benchmark catalysts. This study features the potential application of the Gd-based perovskites in the field of electrocatalysis.