Oxygen deficient layered double perovskite as an active cathode for CO2 electrolysis using a solid oxide conductor

Abstract

A-site ordered PrBaMn2O5+δ was investigated as a potential cathode for CO2 electrolysis using a La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) electrolyte. The A-site ordered layered double perovskite, PrBaMn2O5+δ, was found to enhance electrocatalytic activity for CO2 reduction on the cathode side since it supports mixed valent transition metal cations such as Mn, which could provide high electrical conductivity and maintain a large oxygen vacancy content, contributing to fast oxygen ion diffusion. It was found that during the oxidation of the reduced PrBaMn2O5+δ (O5 phase) to PrBaMn2O6-δ (O6 phase), a reversible oxygen switchover in the lattice takes place. In addition, here the successful CO2 electrolysis was measured in LSGM electrolyte with this novel oxide electrode. It was found that this PrBaMn2O5+δ, layered perovskite cathode exhibits a performance with a current density of 0.85 A cm-2 at 1.5 V and 850 °C and the electrochemical properties were also evaluated by impedance spectroscopy.