Abstract:Bi₂₆Mo₁₀O₆₉ nanopowder was prepared by hydrothermal method and used as a surface modification material for oxygen separation membrane to enhance oxygen permeability. Thermal decomposition behavior and phase variation of the precursor were investigated by thermal analyzer (TG-DSC) and high-temperature X-ray diffraction (HT-XRD). Bi₂₆Mo₁₀O₆₉ porous layer was coated on the air side of BaCo_0.7Fe_0.2Nb_0.1O_3-d (BCFN) oxygen permeable membrane by dipping method. In the partial oxidation experiment of coke oven gas (COG), the Bi₂₆Mo₁₀O₆₉-coated BCFN membrane exhibits higher oxygen permeability and CH₄ conversion than the uncoated BCFN membrane. When the thickness of BCFN membrane was 1 mm and the COG and air fluxes were 120 and 100 mL/min, the oxygen permeation flux reached 16.48 mL/(min·cm²) at 875 °C, which was 16.96% higher than the uncoated BCFN membrane. Therefore, Bi₂₆Mo₁₀O₆₉ porous layer on the air side will be promising modification coating on the oxygen permeability of BCFN membrane.

Key words: Bi₂₆Mo₁₀O₆₉; porous-coating; BaCo_0.7Fe_0.2Nb_0.1O_3-d (BCFN); oxygen permeation flux