Synergistic effects of anionic doping and symmetrical structure for enabling high-performance hydrogen separation in ceramic membranes

Lanthanum tungstate-based mixed protonic-electronic conducting membranes are highly valued in the realm of hydrogen separation due to their exceptional stability and CO 2 resistance. However, the low hydrogen permeability of these membranes has been a limiting factor in their broader application. This study introduces an optimized La 5.5 W 0.6 Mo 0.4 O 11.2-δ Cl 0.1 (LWMCl 0.1 ) hydrogen permeation membrane, featuring a graded porous supported symmetric structure, the fabricated membrane, optimized for improved H 2 flux, has an approximate thickness of 550 μm, achieved a remarkable hydrogen permeation flux of 1.14 mL min −1 cm −2 at 950°C, setting a new record for lanthanum tungstate-based membranes so far. The symmetric graded porous design expands the surface exchange area, thereby reducing surface exchange limitations, while the thin dense layer substantially decreases bulk diffusion resistance. This research proposes an approach to improve the permeability of dense mixed conductor ceramic membranes, purifying hydrogen, and expanding the application scope of membrane reactors. The findings contribute to the advancement of efficient hydrogen separation technologies and underscore the potential of optimized membrane structures in addressing critical energy and environmental challenges.