致密超薄钯膜的制备及其性能研究

DENSE PALLADIUM MEMBRANE: PREPARATION, HYDROGEN PERMEATION AND LONG TERM STABILITY

根据金属Pd的自催化特性 ,采用改进的PCD法制备致密超薄钯膜 ,同时考察了氢分压和操作温度对钯膜氢渗透性能的影响以及氢渗透过程的操作稳定性。结果发现 ,对金属层厚度为 0 .3～ 0 .4μm的超薄Pd/TiO2 复合膜 ,773K时的氢渗透性为 6 .3× 10 -6mol·m-2 ·s-1·Pa-1,H2 /N2 的分离系数为 1140左右。氢渗透超薄钯膜的稳定时间为 80h左右 ,而且钯膜的氢渗透速率在 6 73～

An ultrathin palladium layer was prepared by an improved photocatalytic deposition (PCD) technique on the surface of a porous titania membrane. The thickness of the resulting palladium membrane was about 0.3～0.4 μm. The hydrogen permeability and H\-2/N\-2 selectivity through the palladium composite membrane are 6.3×10 -6 mol·m -2 ·s -1 ·Pa -1 and 1 140 at 773 K, respectively. Long term hydrogen permeation operation at 673 K indicated that the flux through the resulting membrane under hydrogen/nitrogen gradients requires 80 h to reach a steady state. The steady state hydrogen flux showed no observable changes during the thermal cycles between 673 and 773 K.