Preparation of Pd membrane with high permeability and thermal stability on porous YSZ-Al2O3 tubes by two-step CeO2 modification
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. School of Iron and Steel, Soochow University, Suzhou 215000, China;
3. Otto Schott Institute of Materials Research, Friedrich-Schiller-Universit？t Jena, Jena 07743, Germany)
2. School of Iron and Steel, Soochow University, Suzhou 215000, China;
3. Otto Schott Institute of Materials Research, Friedrich-Schiller-Universit？t Jena, Jena 07743, Germany)
Abstract: Pd membranes were deposited on porous YSZ-Al2O3 tubes after different modification methods using an electroless plating technology. SEM, AFM, XRD and gas permeation tests were applied to investigating the effects of different modification methods on the surface quality of porous tubes and the permeation performance of the Pd composite membranes. The results showed that the surface of the porous tubes after the two-step CeO2 modification exhibited smaller pore distribution and roughness. Pd membranes on the porous tubes after the two-step CeO2 modification exhibited higher hydrogen permeation flux (0.549 mol·m-2·s-1) and H2/N2 selectivity (14241) at 500 °C and a pressure difference of 700 kPa. The results of different thermal cycling tests and the long-term permeation tests of 1000 h showed that Pd membranes on the porous tubes after the two-step CeO2 modification had higher permeation stability.
Key words: hydrogen separation; Pd membrane; porous tube; surface modification; CeO2