Realizing stable high hydrogen permeation flux through BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ membrane using a thin Pd film protection strategy

Hydrogen (H₂)-selective membrane is an enabling technology for high purity H₂ production from natural gas. Here, we demonstrate the feasibility to apply BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3-δ (BCFZY), a widely studied MPEC composition with high electronic conductivity as H₂ permeation membrane by sputtering thin Palladium (Pd) films on its feed and permeate surfaces as a protective layer to prevent BCFZY reduction upon long-term exposure to reducing H₂. Pd thin film also acts as a catalytic layer to enhance H₂ dissociation in the feed surface and H association in the permeate surface. Pd-sputtered BCFZY (Pd|BCFZY|Pd) membrane displayed exceptionally high H₂ flux that varies from 0.101 rise to 0.213 mL min⁻¹ cm⁻² (450 °C–650 °C) under the 10% H₂-90% N₂/Argon (Ar) gradient. The attainment of significant H₂ permeability below 500 °C shown here indicates the possibility to lower the operating temperature for H₂ permeation using MPEC materials. Pd|BCFZY|Pd membrane also demonstrated stable, high H₂ flux that fluctuates more or less 0.138 mL min⁻¹ cm⁻² during the continuous operation over 225-h duration.