Multiplying Oxygen Permeability of a Ruddlesden‐Popper Oxide by Orientation Control via Magnets

Abstract

Ruddlesden‐Popper‐type oxides exhibit remarkable chemical stability in comparison to perovskite oxides. However, they display lower oxygen permeability. We present an approach to overcome this trade‐off by leveraging the anisotropic properties of Nd2NiO4+δ. Its (a,b)‐plane, having oxygen diffusion coefficient and surface exchange coefficient several orders of magnitude higher than its c‐axis, can be aligned perpendicular to the gradient of oxygen partial pressure by a magnetic field (0.81 T). A stable and high oxygen flux of 1.40 mL min−1 cm−2 was achieved for at least 120 h at 1223 K by a textured asymmetric disk membrane with 1.0 mm thickness under the pure CO2 sweeping. Its excellent operational stability was also verified even at 1023 K in pure CO2. These findings highlight the significant enhancement in oxygen permeation membrane performance achievable by adjusting the grain orientation. Consequently, Nd2NiO4+δ emerges as a promising candidate for industrial applications in air separation, syngas production, and CO2 capture under harsh conditions.