Advancing oxygen separation: insights from experimental and computational analysis of La0.7Ca0.3Co0.3Fe0.6M0.1O3−δ (M = Cu, Zn) oxygen transport membranes

Abstract

In this study, perovskite-type La_0.7Ca_0.3Co_0.3 Fe_0.6M_0.1O_3−δ (M = Cu, Zn) powders were synthesized using a scalable reverse co-precipitation method, presenting them as novel materials for oxygen transport membranes. The comprehensive study covered various aspects including oxygen permeability, crystal structure, conductivity, morphology, CO₂ tolerance, and long-term regenerative durability with a focus on phase structure and composition. The membrane La_0.7Ca_0.3Co_0.3Fe_0.6Zn_0.1O_3−δ exhibited high oxygen permeation fluxes, reaching up to 0.88 and 0.64 mL·min⁻¹cm⁻² under air/He and air/CO₂ gradients at 1173 K, respectively. After 1600 h of CO₂ exposure, the perovskite structure remained intact, showcasing superior CO₂ resistance. A combination of first principles simulations and experimental measurements was employed to deepen the understanding of Cu/Zn substitution effects on the structure, oxygen vacancy formation, and transport behavior of the membranes. These findings underscore the potential of this highly CO₂-tolerant membrane for applications in high-temperature oxygen separation. The enhanced insights into the oxygen transport mechanism contribute to the advancement of next-generation membrane materials.