Design of CO-Resistant High-Entropy Perovskites Based on BaSrCoFeO Materials.

High-entropy perovskite materials (HEPMs), characterized by their multi-element composition and highly disordered structure, can incorporate multiple rare earth elements at the A-site, producing perovskites with enhanced CO resistance, making them stay high performance and structurally stable in the CO atmosphere. However, this modification may result in reduced oxygen permeability. In this study, we investigated LaPrNdBaSrCoFeO (LM) high-entropy perovskite materials, focusing on enhancing their oxygen permeability in both air and CO atmospheres through strategic design modifications at the B-sites and A/B-sites. We prepared Ni-substituted LaPrNdBaSrCoFeNiO (LMN) HEPMs by introducing Ni elements at the B-site, and further innovatively introduced A-site defects to prepare LaPrNdBaSrCoFeNiO (LMN) materials. In a pure CO atmosphere, the oxygen permeation flux of the LMN membrane can reach 0.29 mL·cm·min. Notably, the LMN membrane maintained a good perovskite structure after stability tests extending up to 120 h under 20% CO/80% He atmosphere. These findings suggest that A-site-defect high-entropy perovskites hold great promise for applications in CO capture, storage, and utilization.