On the long-term stability of Pd-membranes with TiO2 intermediate layers for H2 purification

This work addresses the use of TiO2-based particles as an intermediate layer for reaching fully dense Pd-membranes by Electroless Pore-Plating long-time hydrogen separation. Two different layers formed raw and Pd-doped TiO2 were considered. The estimated Pd-thickness composite membrane was reduced in half when ceramic doped with Pd nuclei before their incorporation onto porous support vacuum-assisted dip-coating. real thickness top Pd-film even lower (around 3 ?m), evidenced cross-section SEM images. However, a certain amount palladium penetrates some points structure up to 50 ?m depth. In this manner, despite saving noticeable during fabrication, H2-permeance found while permeating pure from inner outer surface at 400 °C (3.55·10?4 against 4.59·10?4 mol m?2 s?1 Pa?0.5). Certain concentration-polarization case feeding binary H2–N2 mixtures all conditions, especially permeation process. Similarly, effect using sweep gas is more significant applied on side where placed. Besides, both membranes showed good mechanical stability around 200 h, obtaining complete H2/N2 ideal separation factor entire set experiments. At point, value decreased prepared (TiO2/Pd). same time, selectivity maintained 1000 h (Pd–TiO2/Pd). specific decrease H2-permeate flux operating 450 due possible alloy between titanium that not temperature (400 °C). Therefore, Pd–TiO2/Pd could be very attractive used under stable operation either independent separators or reactors which moderate temperatures are required.