超薄Pd～Cu／Al2O3合金膜的透氢性能

Hydrogen permeation performances of ultra-thin composite Pd-Cu/Al_2O_3 alloy membranes

以多孔Al2O3陶瓷管为基体，采用化学镀法分步沉积Pd和Cu金属层，再经高温合金化处理，制备组分不同的Pd—Cu合金膜，膜厚均约为4μm．研究合金膜在100—650℃范围内的透氢性能，考察温度和膜组成对透氢性能的影响．结果表明：H2在膜表面的扩散过程是H2渗透速率的主要控制步骤；温度对膜透氢性能的影响规律因膜组成而异，这可能与合金膜在不同组成、不同温度条件下所呈现的晶相结构有关．

Pd-Cu alloy membranes with different compositions were prepared on porous Al2O3 tube by sequential deposition of Pd and Cu layers via electroless plating followed by an alloying heat treatment, and the thickness of the resulting alloy membranes was 4 μm. The hydrogen permeation performances of the membranes at 100 - 650 ℃, and the effects of the temperature and the membrane composition were studied. Result showed that the hydrogen diffusion on the membrane surface was the mainly rate-determining step for the hydrogen permeation. The temperature influences on the membranes with different compositions were dramatically different. It might be associated with the existence of different crystalline struc- tures at different temperatures and membrane compositions.