Y-La,Y-Nd,Y-Pr混合稀土元素对化学镀制备钯复合膜的影响

Research on Preparation of Palladium Inorganic Composite Membraneby New Rare Earths-Electroless Plating Technique

采用稀土化学镀新工艺制备钯 /α -Al2 O3 无机复合膜 .重点研究了在镀液中添加混合稀土元素对钯的沉积速度、镀膜温度和膜表面结构的影响 .用扫描电镜对钯膜表面形貌进行了表征 .结果表明 :在镀液中分别适量添加Y -La,Y -Nd和Y -Pr等混合稀土元素 ,可提高镀速、降低镀温、缩小钯膜的晶核尺寸和提高膜的致密性 .制得的钯顶膜厚约 5 μm ,在 35 0℃和 0 .3MPa下 ,氢的渗透系数为 2 .85× 10 -12 (mol·m) / (m·s·Pa0 .5) ,从H2 -N2 混合气中可分离出纯度为 99.97%的氢气 .

The new rare earths-electroless plating technique was developed to prepare palladium composite membrane in this article.More attentions were paid to the studies of the effects of the rare earth elements added in the plating solution on the Pd deposition rate,plating temperature and membrane surface structure.The membrane surface structure was evaluated by SEM.The experimental results show that the additions of suitable amount of mixed rare earth elements (Y-La,Y-Nd,Y-Pr) into the traditional plating solution can increase the Pd deposition rate,reduce the plating temperature,shrink the size of Pd crystals and improve the film density. The thickness of the prepared palladium membrane is about 5 μm.The hydrogen permeability coefficient through the film is 2.85×10 -12 (mol·m)/(m·s·Pa 0.5 ) at 350 ℃ and 0.3 MPa.Hydrogen with purity of 99.97% can be separated from H 2-N 2 gas mixture using this membrane.